56621 has 4 divisors (see below), whose sum is σ = 58044. Its totient is φ = 55200.

The previous prime is 56611. The next prime is 56629. The reversal of 56621 is 12665.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12100 + 44521 = 110^2 + 211^2 .

It is a cyclic number.

It is not a de Polignac number, because 56621 - 2¹⁴ = 40237 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 56593 and 56602.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 56621.

It is not an unprimeable number, because it can be changed into a prime (56629) 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, 650 + ... + 731.

It is an arithmetic number, because the mean of its divisors is an integer number (14511).

2⁵⁶⁶²¹ is an apocalyptic number.

It is an amenable number.

56621 is a deficient number, since it is larger than the sum of its proper divisors (1423).

56621 is a wasteful number, since it uses less digits than its factorization.

56621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1422.

The product of its digits is 360, while the sum is 20.

The square root of 56621 is about 237.9516757663. The cubic root of 56621 is about 38.3995243720.

Subtracting from 56621 its reverse (12665), we obtain a triangular number (43956 = T₂₉₆).

The spelling of 56621 in words is "fifty-six thousand, six hundred twenty-one".