311998161 has 16 divisors (see below), whose sum is σ = 442044864. Its totient is φ = 195062784.

The previous prime is 311998157. The next prime is 311998177. The reversal of 311998161 is 161899113.

It is not a de Polignac number, because 311998161 - 2² = 311998157 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (311998261) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3625 + ... + 25241.

It is an arithmetic number, because the mean of its divisors is an integer number (27627804).

Almost surely, 2^311998161 is an apocalyptic number.

It is an amenable number.

311998161 is a deficient number, since it is larger than the sum of its proper divisors (130046703).

311998161 is a wasteful number, since it uses less digits than its factorization.

311998161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21920.

The product of its digits is 11664, while the sum is 39.

The square root of 311998161 is about 17663.4696761423. The cubic root of 311998161 is about 678.2409560280.

The spelling of 311998161 in words is "three hundred eleven million, nine hundred ninety-eight thousand, one hundred sixty-one".