156856394621 has 2 divisors, whose sum is σ = 156856394622. Its totient is φ = 156856394620.

The previous prime is 156856394593. The next prime is 156856394627. The reversal of 156856394621 is 126493658651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 156389402521 + 466992100 = 395461^2 + 21610^2 .

It is a cyclic number.

It is not a de Polignac number, because 156856394621 - 2²² = 156852200317 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (156856394627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78428197310 + 78428197311.

It is an arithmetic number, because the mean of its divisors is an integer number (78428197311).

Almost surely, 2^156856394621 is an apocalyptic number.

It is an amenable number.

156856394621 is a deficient number, since it is larger than the sum of its proper divisors (1).

156856394621 is an equidigital number, since it uses as much as digits as its factorization.

156856394621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9331200, while the sum is 56.

The spelling of 156856394621 in words is "one hundred fifty-six billion, eight hundred fifty-six million, three hundred ninety-four thousand, six hundred twenty-one".