161311793231 has 4 divisors (see below), whose sum is σ = 161314691352. Its totient is φ = 161308895112.

The previous prime is 161311793191. The next prime is 161311793233. The reversal of 161311793231 is 132397113161.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161311793231 is a prime.

It is a super-2 number, since 2×161311793231² (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 (161311793233) 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, 1363901 + ... + 1477446.

It is an arithmetic number, because the mean of its divisors is an integer number (40328672838).

Almost surely, 2^161311793231 is an apocalyptic number.

161311793231 is a deficient number, since it is larger than the sum of its proper divisors (2898121).

161311793231 is an equidigital number, since it uses as much as digits as its factorization.

161311793231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2898120.

The product of its digits is 20412, while the sum is 38.

The spelling of 161311793231 in words is "one hundred sixty-one billion, three hundred eleven million, seven hundred ninety-three thousand, two hundred thirty-one".