56021557 has 16 divisors (see below), whose sum is σ = 61286400. Its totient is φ = 51012720.

The previous prime is 56021551. The next prime is 56021573. The reversal of 56021557 is 75512065.

It is not a de Polignac number, because 56021557 - 2³ = 56021549 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56021551) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 133494 + ... + 133912.

It is an arithmetic number, because the mean of its divisors is an integer number (3830400).

Almost surely, 2^56021557 is an apocalyptic number.

It is an amenable number.

56021557 is a deficient number, since it is larger than the sum of its proper divisors (5264843).

56021557 is a wasteful number, since it uses less digits than its factorization.

56021557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 696.

The product of its (nonzero) digits is 10500, while the sum is 31.

The square root of 56021557 is about 7484.7549726093. The cubic root of 56021557 is about 382.6353219917.

The spelling of 56021557 in words is "fifty-six million, twenty-one thousand, five hundred fifty-seven".