311399991 has 32 divisors (see below), whose sum is σ = 544256000. Its totient is φ = 172199520.

The previous prime is 311399971. The next prime is 311399993. The reversal of 311399991 is 199993113.

It is not a de Polignac number, because 311399991 - 2⁹ = 311399479 is a prime.

It is a nude number because it is divisible by every one of its digits.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (311399993) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20716 + ... + 32433.

It is an arithmetic number, because the mean of its divisors is an integer number (17008000).

Almost surely, 2^311399991 is an apocalyptic number.

311399991 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

311399991 is a deficient number, since it is larger than the sum of its proper divisors (232856009).

311399991 is a wasteful number, since it uses less digits than its factorization.

311399991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53196 (or 53190 counting only the distinct ones).

The product of its digits is 59049, while the sum is 45.

The square root of 311399991 is about 17646.5291488156. The cubic root of 311399991 is about 677.8072323778.

The spelling of 311399991 in words is "three hundred eleven million, three hundred ninety-nine thousand, nine hundred ninety-one".