56816537821 has 2 divisors, whose sum is σ = 56816537822. Its totient is φ = 56816537820.

The previous prime is 56816537803. The next prime is 56816537837. The reversal of 56816537821 is 12873561865.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 52527597721 + 4288940100 = 229189^2 + 65490^2 .

It is a cyclic number.

It is not a de Polignac number, because 56816537821 - 2⁷ = 56816537693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56816537861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28408268910 + 28408268911.

It is an arithmetic number, because the mean of its divisors is an integer number (28408268911).

Almost surely, 2^56816537821 is an apocalyptic number.

It is an amenable number.

56816537821 is a deficient number, since it is larger than the sum of its proper divisors (1).

56816537821 is an equidigital number, since it uses as much as digits as its factorization.

56816537821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2419200, while the sum is 52.

The spelling of 56816537821 in words is "fifty-six billion, eight hundred sixteen million, five hundred thirty-seven thousand, eight hundred twenty-one".