157891771121 has 4 divisors (see below), whose sum is σ = 180447738432. Its totient is φ = 135335803812.

The previous prime is 157891771117. The next prime is 157891771127. The reversal of 157891771121 is 121177198751.

It is a happy number.

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 157891771121 - 2² = 157891771117 is a prime.

It is a super-2 number, since 2×157891771121² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 157891771121.

It is not an unprimeable number, because it can be changed into a prime (157891771127) 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, 11277983645 + ... + 11277983658.

It is an arithmetic number, because the mean of its divisors is an integer number (45111934608).

Almost surely, 2^157891771121 is an apocalyptic number.

It is an amenable number.

157891771121 is a deficient number, since it is larger than the sum of its proper divisors (22555967311).

157891771121 is an equidigital number, since it uses as much as digits as its factorization.

157891771121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22555967310.

The product of its digits is 246960, while the sum is 50.

The spelling of 157891771121 in words is "one hundred fifty-seven billion, eight hundred ninety-one million, seven hundred seventy-one thousand, one hundred twenty-one".