56521389 has 4 divisors (see below), whose sum is σ = 75361856. Its totient is φ = 37680924.

The previous prime is 56521363. The next prime is 56521403. The reversal of 56521389 is 98312565.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 56521389 - 2¹¹ = 56519341 is a prime.

It is a super-4 number, since 4×56521389⁴ (a number of 32 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56525389) 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, 9420229 + ... + 9420234.

It is an arithmetic number, because the mean of its divisors is an integer number (18840464).

Almost surely, 2^56521389 is an apocalyptic number.

It is an amenable number.

56521389 is a deficient number, since it is larger than the sum of its proper divisors (18840467).

56521389 is a wasteful number, since it uses less digits than its factorization.

56521389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18840466.

The product of its digits is 64800, while the sum is 39.

The square root of 56521389 is about 7518.0708296743. The cubic root of 56521389 is about 383.7699291853.

The spelling of 56521389 in words is "fifty-six million, five hundred twenty-one thousand, three hundred eighty-nine".