56516421 has 16 divisors (see below), whose sum is σ = 81361280. Its totient is φ = 34689600.

The previous prime is 56516407. The next prime is 56516423. The reversal of 56516421 is 12461565.

It is not a de Polignac number, because 56516421 - 2⁶ = 56516357 is a prime.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56516423) 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, 15471 + ... + 18771.

It is an arithmetic number, because the mean of its divisors is an integer number (5085080).

Almost surely, 2^56516421 is an apocalyptic number.

It is an amenable number.

56516421 is a deficient number, since it is larger than the sum of its proper divisors (24844859).

56516421 is a wasteful number, since it uses less digits than its factorization.

56516421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3756.

The product of its digits is 7200, while the sum is 30.

The square root of 56516421 is about 7517.7404185034. The cubic root of 56516421 is about 383.7586849177.

Adding to 56516421 its reverse (12461565), we get a palindrome (68977986).

The spelling of 56516421 in words is "fifty-six million, five hundred sixteen thousand, four hundred twenty-one".