28400656 has 10 divisors (see below), whose sum is σ = 55026302. Its totient is φ = 14200320.

The previous prime is 28400623. The next prime is 28400663. The reversal of 28400656 is 65600482.

It can be written as a sum of positive squares in only one way, i.e., 20106256 + 8294400 = 4484^2 + 2880^2 .

It is a super-2 number, since 2×28400656² = 1613194522460672, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 887505 + ... + 887536.

Almost surely, 2^28400656 is an apocalyptic number.

It is an amenable number.

28400656 is a deficient number, since it is larger than the sum of its proper divisors (26625646).

28400656 is a wasteful number, since it uses less digits than its factorization.

28400656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1775049 (or 1775043 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 28400656 is about 5329.2265855375. The cubic root of 28400656 is about 305.1004094738.

The spelling of 28400656 in words is "twenty-eight million, four hundred thousand, six hundred fifty-six".