28072656 has 50 divisors (see below), whose sum is σ = 81254162. Its totient is φ = 9357120.

The previous prime is 28072651. The next prime is 28072687. The reversal of 28072656 is 65627082.

It can be written as a sum of positive squares in only one way, i.e., 21902400 + 6170256 = 4680^2 + 2484^2 .

It is a Smith number, since the sum of its digits (36) 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 (36).

It is a self number, because there is not a number n which added to its sum of digits gives 28072656.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28072651) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 9535 + ... + 12126.

Almost surely, 2^28072656 is an apocalyptic number.

It is an amenable number.

28072656 is an abundant number, since it is smaller than the sum of its proper divisors (53181506).

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

28072656 is a wasteful number, since it uses less digits than its factorization.

28072656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21681 (or 21666 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The square root of 28072656 is about 5298.3635209374. The cubic root of 28072656 is about 303.9213208205.

The spelling of 28072656 in words is "twenty-eight million, seventy-two thousand, six hundred fifty-six".