21957368285137 has 2 divisors, whose sum is σ = 21957368285138. Its totient is φ = 21957368285136.

The previous prime is 21957368285077. The next prime is 21957368285143. The reversal of 21957368285137 is 73158286375912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20967231842001 + 990136443136 = 4578999^2 + 995056^2 .

It is a cyclic number.

It is not a de Polignac number, because 21957368285137 - 2²⁷ = 21957234067409 is a prime.

It is not a weakly prime, because it can be changed into another prime (21957368286137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10978684142568 + 10978684142569.

It is an arithmetic number, because the mean of its divisors is an integer number (10978684142569).

Almost surely, 2^{21957368285137} is an apocalyptic number.

It is an amenable number.

21957368285137 is a deficient number, since it is larger than the sum of its proper divisors (1).

21957368285137 is an equidigital number, since it uses as much as digits as its factorization.

21957368285137 is an evil number, because the sum of its binary digits is even.

The product of its digits is 152409600, while the sum is 67.

The spelling of 21957368285137 in words is "twenty-one trillion, nine hundred fifty-seven billion, three hundred sixty-eight million, two hundred eighty-five thousand, one hundred thirty-seven".