56543621 has 2 divisors, whose sum is σ = 56543622. Its totient is φ = 56543620.

The previous prime is 56543593. The next prime is 56543623. The reversal of 56543621 is 12634565.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49984900 + 6558721 = 7070^2 + 2561^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-56543621 is a prime.

It is a Sophie Germain prime.

Together with 56543623, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56543623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28271810 + 28271811.

It is an arithmetic number, because the mean of its divisors is an integer number (28271811).

Almost surely, 2^56543621 is an apocalyptic number.

It is an amenable number.

56543621 is a deficient number, since it is larger than the sum of its proper divisors (1).

56543621 is an equidigital number, since it uses as much as digits as its factorization.

56543621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21600, while the sum is 32.

The square root of 56543621 is about 7519.5492551083. The cubic root of 56543621 is about 383.8202396655.

The spelling of 56543621 in words is "fifty-six million, five hundred forty-three thousand, six hundred twenty-one".