28307656 has 16 divisors (see below), whose sum is σ = 57159900. Its totient is φ = 13065024.

The previous prime is 28307651. The next prime is 28307689. The reversal of 28307656 is 65670382.

It can be written as a sum of positive squares in 2 ways, for example, as 28196100 + 111556 = 5310^2 + 334^2 .

It is not an unprimeable number, because it can be changed into a prime (28307651) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 135991 + ... + 136198.

Almost surely, 2^28307656 is an apocalyptic number.

28307656 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

28307656 is an abundant number, since it is smaller than the sum of its proper divisors (28852244).

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

28307656 is a wasteful number, since it uses less digits than its factorization.

28307656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272208 (or 272204 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 37.

The square root of 28307656 is about 5320.4939620302. The cubic root of 28307656 is about 304.7670208622.

The spelling of 28307656 in words is "twenty-eight million, three hundred seven thousand, six hundred fifty-six".