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20731228 = 2271797449
BaseRepresentation
bin100111100010…
…1010101011100
31110000020220021
41033011111130
520301344403
62020201524
7341132620
oct117052534
943006807
1020731228
111077a751
126b392a4
1343ab1cb
142a79180
151c478bd
hex13c555c

20731228 has 48 divisors (see below), whose sum is σ = 44452800. Its totient is φ = 8257536.

The previous prime is 20731189. The next prime is 20731231. The reversal of 20731228 is 82213702.

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 15 ways as a sum of consecutive naturals, for example, 45948 + ... + 46396.

It is an arithmetic number, because the mean of its divisors is an integer number (926100).

Almost surely, 220731228 is an apocalyptic number.

20731228 is a gapful number since it is divisible by the number (28) 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 20731228, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22226400).

20731228 is an abundant number, since it is smaller than the sum of its proper divisors (23721572).

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

20731228 is a wasteful number, since it uses less digits than its factorization.

20731228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 574 (or 572 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 20731228 is about 4553.1558286534. The cubic root of 20731228 is about 274.7103418414.

The spelling of 20731228 in words is "twenty million, seven hundred thirty-one thousand, two hundred twenty-eight".

Divisors: 1 2 4 7 14 17 28 34 68 97 119 194 238 388 449 476 679 898 1358 1649 1796 2716 3143 3298 6286 6596 7633 11543 12572 15266 23086 30532 43553 46172 53431 87106 106862 174212 213724 304871 609742 740401 1219484 1480802 2961604 5182807 10365614 20731228