231966388531 has 4 divisors (see below), whose sum is σ = 231985777864. Its totient is φ = 231946999200.

The previous prime is 231966388523. The next prime is 231966388547. The reversal of 231966388531 is 135883669132.

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

It is a cyclic number.

It is not a de Polignac number, because 231966388531 - 2³ = 231966388523 is a prime.

It is a super-2 number, since 2×231966388531² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231966388231) 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, 9676710 + ... + 9700651.

It is an arithmetic number, because the mean of its divisors is an integer number (57996444466).

Almost surely, 2^231966388531 is an apocalyptic number.

231966388531 is a deficient number, since it is larger than the sum of its proper divisors (19389333).

231966388531 is a wasteful number, since it uses less digits than its factorization.

231966388531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19389332.

The product of its digits is 5598720, while the sum is 55.

The spelling of 231966388531 in words is "two hundred thirty-one billion, nine hundred sixty-six million, three hundred eighty-eight thousand, five hundred thirty-one".