231312221231 has 32 divisors (see below), whose sum is σ = 297154787328. Its totient is φ = 175009000320.

The previous prime is 231312221221. The next prime is 231312221291. The reversal of 231312221231 is 132122213132.

It is not a de Polignac number, because 231312221231 - 2⁶ = 231312221167 is a prime.

It is a super-2 number, since 2×231312221231² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a junction number, because it is equal to n+sod(n) for n = 231312221197 and 231312221206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231312221221) 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, 8372861 + ... + 8400441.

It is an arithmetic number, because the mean of its divisors is an integer number (9286087104).

Almost surely, 2^231312221231 is an apocalyptic number.

231312221231 is a deficient number, since it is larger than the sum of its proper divisors (65842566097).

231312221231 is a wasteful number, since it uses less digits than its factorization.

231312221231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31631.

The product of its digits is 864, while the sum is 23.

Adding to 231312221231 its reverse (132122213132), we get a palindrome (363434434363).

The spelling of 231312221231 in words is "two hundred thirty-one billion, three hundred twelve million, two hundred twenty-one thousand, two hundred thirty-one".