28712656 has 20 divisors (see below), whose sum is σ = 63578272. Its totient is φ = 12305376.

The previous prime is 28712653. The next prime is 28712657. The reversal of 28712656 is 65621782.

It is a happy number.

It is a super-2 number, since 2×28712656² = 1648833229148672, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28712653) 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, 128070 + ... + 128293.

Almost surely, 2^28712656 is an apocalyptic number.

It is an amenable number.

28712656 is an abundant number, since it is smaller than the sum of its proper divisors (34865616).

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

28712656 is a wasteful number, since it uses less digits than its factorization.

28712656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256378 (or 256372 counting only the distinct ones).

The product of its digits is 40320, while the sum is 37.

The square root of 28712656 is about 5358.4191698672. The cubic root of 28712656 is about 306.2135863411.

The spelling of 28712656 in words is "twenty-eight million, seven hundred twelve thousand, six hundred fifty-six".