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28438872 = 23371121399
BaseRepresentation
bin110110001111…
…1000101011000
31222111211210120
41230133011120
524240020442
62453313240
7463504110
oct154370530
958454716
1028438872
1115064600
129635820
135b79547
143ac4040
15276b4ec
hex1b1f158

28438872 has 96 divisors (see below), whose sum is σ = 89376000. Its totient is φ = 7381440.

The previous prime is 28438853. The next prime is 28438889. The reversal of 28438872 is 27883482.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19629 + ... + 21027.

It is an arithmetic number, because the mean of its divisors is an integer number (931000).

Almost surely, 228438872 is an apocalyptic number.

28438872 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28438872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44688000).

28438872 is an abundant number, since it is smaller than the sum of its proper divisors (60937128).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28438872 is a wasteful number, since it uses less digits than its factorization.

28438872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1437 (or 1422 counting only the distinct ones).

The product of its digits is 172032, while the sum is 42.

The square root of 28438872 is about 5332.8108910780. The cubic root of 28438872 is about 305.2371961191.

The spelling of 28438872 in words is "twenty-eight million, four hundred thirty-eight thousand, eight hundred seventy-two".

Divisors: 1 2 3 4 6 7 8 11 12 14 21 22 24 28 33 42 44 56 66 77 84 88 121 132 154 168 231 242 264 308 363 462 484 616 726 847 924 968 1399 1452 1694 1848 2541 2798 2904 3388 4197 5082 5596 6776 8394 9793 10164 11192 15389 16788 19586 20328 29379 30778 33576 39172 46167 58758 61556 78344 92334 107723 117516 123112 169279 184668 215446 235032 323169 338558 369336 430892 507837 646338 677116 861784 1015674 1184953 1292676 1354232 2031348 2369906 2585352 3554859 4062696 4739812 7109718 9479624 14219436 28438872