56401566 has 64 divisors (see below), whose sum is σ = 128217600. Its totient is φ = 16410240.

The previous prime is 56401561. The next prime is 56401567. The reversal of 56401566 is 66510465.

It is a super-2 number, since 2×56401566² = 6362273294504712, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56401561) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 267201 + ... + 267411.

It is an arithmetic number, because the mean of its divisors is an integer number (2003400).

Almost surely, 2^56401566 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 56401566, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (64108800).

56401566 is an abundant number, since it is smaller than the sum of its proper divisors (71816034).

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

56401566 is a wasteful number, since it uses less digits than its factorization.

56401566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 401.

The product of its (nonzero) digits is 21600, while the sum is 33.

The square root of 56401566 is about 7510.0976025615. The cubic root of 56401566 is about 383.4985452106.

The spelling of 56401566 in words is "fifty-six million, four hundred one thousand, five hundred sixty-six".