157977291581 has 4 divisors (see below), whose sum is σ = 158055230112. Its totient is φ = 157899353052.

The previous prime is 157977291557. The next prime is 157977291583. The reversal of 157977291581 is 185192779751.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 157977291581 - 2³⁴ = 140797422397 is a prime.

It is a super-2 number, since 2×157977291581² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (157977291583) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38966225 + ... + 38970278.

It is an arithmetic number, because the mean of its divisors is an integer number (39513807528).

Almost surely, 2^157977291581 is an apocalyptic number.

It is an amenable number.

157977291581 is a deficient number, since it is larger than the sum of its proper divisors (77938531).

157977291581 is an equidigital number, since it uses as much as digits as its factorization.

157977291581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77938530.

The product of its digits is 11113200, while the sum is 62.

The spelling of 157977291581 in words is "one hundred fifty-seven billion, nine hundred seventy-seven million, two hundred ninety-one thousand, five hundred eighty-one".