231691911 has 16 divisors (see below), whose sum is σ = 341276160. Its totient is φ = 138640320.

The previous prime is 231691907. The next prime is 231691913. The reversal of 231691911 is 119196132.

It is not a de Polignac number, because 231691911 - 2² = 231691907 is a prime.

It is a super-2 number, since 2×231691911² = 107362283245663842, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231691913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41830 + ... + 47043.

It is an arithmetic number, because the mean of its divisors is an integer number (21329760).

Almost surely, 2^231691911 is an apocalyptic number.

231691911 is a deficient number, since it is larger than the sum of its proper divisors (109584249).

231691911 is a wasteful number, since it uses less digits than its factorization.

231691911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88966.

The product of its digits is 2916, while the sum is 33.

The square root of 231691911 is about 15221.4293349869. The cubic root of 231691911 is about 614.1912483776.

The spelling of 231691911 in words is "two hundred thirty-one million, six hundred ninety-one thousand, nine hundred eleven".