56501521 has 4 divisors (see below), whose sum is σ = 57061044. Its totient is φ = 55942000.

The previous prime is 56501509. The next prime is 56501537. The reversal of 56501521 is 12510565.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12510565 = 5 ⋅2502113.

It can be written as a sum of positive squares in 2 ways, for example, as 39187600 + 17313921 = 6260^2 + 4161^2 .

It is a cyclic number.

It is not a de Polignac number, because 56501521 - 2¹¹ = 56499473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (56501581) 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, 279610 + ... + 279811.

It is an arithmetic number, because the mean of its divisors is an integer number (14265261).

Almost surely, 2^56501521 is an apocalyptic number.

It is an amenable number.

56501521 is a deficient number, since it is larger than the sum of its proper divisors (559523).

56501521 is a wasteful number, since it uses less digits than its factorization.

56501521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 559522.

The product of its (nonzero) digits is 1500, while the sum is 25.

The square root of 56501521 is about 7516.7493639206. The cubic root of 56501521 is about 383.7249572159.

The spelling of 56501521 in words is "fifty-six million, five hundred one thousand, five hundred twenty-one".