56251621 has 4 divisors (see below), whose sum is σ = 57448512. Its totient is φ = 55054732.

The previous prime is 56251597. The next prime is 56251651. The reversal of 56251621 is 12615265.

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 a cyclic number.

It is not a de Polignac number, because 56251621 - 2⁹ = 56251109 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 56251621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56251651) 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, 598375 + ... + 598468.

It is an arithmetic number, because the mean of its divisors is an integer number (14362128).

Almost surely, 2^56251621 is an apocalyptic number.

It is an amenable number.

56251621 is a deficient number, since it is larger than the sum of its proper divisors (1196891).

56251621 is a wasteful number, since it uses less digits than its factorization.

56251621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1196890.

The product of its digits is 3600, while the sum is 28.

The square root of 56251621 is about 7500.1080658881. The cubic root of 56251621 is about 383.1583967172.

Adding to 56251621 its reverse (12615265), we get a palindrome (68866886).

The spelling of 56251621 in words is "fifty-six million, two hundred fifty-one thousand, six hundred twenty-one".