56665809 has 36 divisors (see below), whose sum is σ = 87727536. Its totient is φ = 35236944.

The previous prime is 56665793. The next prime is 56665823. The reversal of 56665809 is 90856665.

It is not a de Polignac number, because 56665809 - 2⁴ = 56665793 is a prime.

It is a super-2 number, since 2×56665809² = 6422027819248962, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (56665309) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 347562 + ... + 347724.

It is an arithmetic number, because the mean of its divisors is an integer number (2436876).

Almost surely, 2^56665809 is an apocalyptic number.

It is an amenable number.

56665809 is a deficient number, since it is larger than the sum of its proper divisors (31061727).

56665809 is a wasteful number, since it uses less digits than its factorization.

56665809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314 (or 292 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The square root of 56665809 is about 7527.6695596977. The cubic root of 56665809 is about 384.0965130129.

The spelling of 56665809 in words is "fifty-six million, six hundred sixty-five thousand, eight hundred nine".