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28718380 = 2251435919
BaseRepresentation
bin110110110001…
…1010100101100
32000001001012201
41231203110230
524322442010
62503311244
7466050025
oct155432454
960031181
1028718380
11152355a9
12974b524
135c46832
143b57c4c
1527c423a
hex1b6352c

28718380 has 12 divisors (see below), whose sum is σ = 60308640. Its totient is φ = 11487344.

The previous prime is 28718353. The next prime is 28718387. The reversal of 28718380 is 8381782.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28718387) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 717940 + ... + 717979.

It is an arithmetic number, because the mean of its divisors is an integer number (5025720).

Almost surely, 228718380 is an apocalyptic number.

28718380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28718380 is an abundant number, since it is smaller than the sum of its proper divisors (31590260).

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

28718380 is a wasteful number, since it uses less digits than its factorization.

28718380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1435928 (or 1435926 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 37.

The square root of 28718380 is about 5358.9532560007. The cubic root of 28718380 is about 306.2339333512.

The spelling of 28718380 in words is "twenty-eight million, seven hundred eighteen thousand, three hundred eighty".

Divisors: 1 2 4 5 10 20 1435919 2871838 5743676 7179595 14359190 28718380