56821867237 has 2 divisors, whose sum is σ = 56821867238. Its totient is φ = 56821867236.

The previous prime is 56821867231. The next prime is 56821867247. The reversal of 56821867237 is 73276812865.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 53232179841 + 3589687396 = 230721^2 + 59914^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-56821867237 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56821867231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28410933618 + 28410933619.

It is an arithmetic number, because the mean of its divisors is an integer number (28410933619).

Almost surely, 2^56821867237 is an apocalyptic number.

It is an amenable number.

56821867237 is a deficient number, since it is larger than the sum of its proper divisors (1).

56821867237 is an equidigital number, since it uses as much as digits as its factorization.

56821867237 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6773760, while the sum is 55.

The spelling of 56821867237 in words is "fifty-six billion, eight hundred twenty-one million, eight hundred sixty-seven thousand, two hundred thirty-seven".