56231821 has 2 divisors, whose sum is σ = 56231822. Its totient is φ = 56231820.

The previous prime is 56231743. The next prime is 56231837. The reversal of 56231821 is 12813265.

56231821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51984100 + 4247721 = 7210^2 + 2061^2 .

It is a cyclic number.

It is not a de Polignac number, because 56231821 - 2⁹ = 56231309 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 56231821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56231221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28115910 + 28115911.

It is an arithmetic number, because the mean of its divisors is an integer number (28115911).

Almost surely, 2^56231821 is an apocalyptic number.

It is an amenable number.

56231821 is a deficient number, since it is larger than the sum of its proper divisors (1).

56231821 is an equidigital number, since it uses as much as digits as its factorization.

56231821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2880, while the sum is 28.

The square root of 56231821 is about 7498.7879687320. The cubic root of 56231821 is about 383.1134354852.

The spelling of 56231821 in words is "fifty-six million, two hundred thirty-one thousand, eight hundred twenty-one".