156516605981 has 2 divisors, whose sum is σ = 156516605982. Its totient is φ = 156516605980.

The previous prime is 156516605951. The next prime is 156516606073. The reversal of 156516605981 is 189506615651.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 147558929956 + 8957676025 = 384134^2 + 94645^2 .

It is a cyclic number.

It is not a de Polignac number, because 156516605981 - 2²⁶ = 156449497117 is a prime.

It is a super-2 number, since 2×156516605981² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (156516605951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78258302990 + 78258302991.

It is an arithmetic number, because the mean of its divisors is an integer number (78258302991).

Almost surely, 2^156516605981 is an apocalyptic number.

It is an amenable number.

156516605981 is a deficient number, since it is larger than the sum of its proper divisors (1).

156516605981 is an equidigital number, since it uses as much as digits as its factorization.

156516605981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1944000, while the sum is 53.

The spelling of 156516605981 in words is "one hundred fifty-six billion, five hundred sixteen million, six hundred five thousand, nine hundred eighty-one".