157721496931 has 8 divisors (see below), whose sum is σ = 160082331920. Its totient is φ = 155360861568.

The previous prime is 157721496871. The next prime is 157721496941. The reversal of 157721496931 is 139694127751.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 157721496931 - 2²³ = 157713108323 is a prime.

It is a super-2 number, since 2×157721496931² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (157721496941) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2537335 + ... + 2598751.

It is an arithmetic number, because the mean of its divisors is an integer number (20010291490).

Almost surely, 2^157721496931 is an apocalyptic number.

157721496931 is a deficient number, since it is larger than the sum of its proper divisors (2360834989).

157721496931 is an equidigital number, since it uses as much as digits as its factorization.

157721496931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99813.

The product of its digits is 2857680, while the sum is 55.

The spelling of 157721496931 in words is "one hundred fifty-seven billion, seven hundred twenty-one million, four hundred ninety-six thousand, nine hundred thirty-one".