231249999981 has 32 divisors (see below), whose sum is σ = 413986019328. Its totient is φ = 110889109440.

The previous prime is 231249999977. The next prime is 231249999983. The reversal of 231249999981 is 189999942132.

It is not a de Polignac number, because 231249999981 - 2² = 231249999977 is a prime.

It is a super-2 number, since 2×231249999981² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231249999983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 38500161 + ... + 38506166.

It is an arithmetic number, because the mean of its divisors is an integer number (12937063104).

Almost surely, 2^231249999981 is an apocalyptic number.

231249999981 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

231249999981 is a deficient number, since it is larger than the sum of its proper divisors (182736019347).

231249999981 is a wasteful number, since it uses less digits than its factorization.

231249999981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77006361.

The product of its digits is 22674816, while the sum is 66.

The spelling of 231249999981 in words is "two hundred thirty-one billion, two hundred forty-nine million, nine hundred ninety-nine thousand, nine hundred eighty-one".