231223156631 has 4 divisors (see below), whose sum is σ = 231225588264. Its totient is φ = 231220725000.

The previous prime is 231223156607. The next prime is 231223156639. The reversal of 231223156631 is 136651322132.

It is a happy number.

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 231223156631 - 2¹⁰ = 231223155607 is a prime.

It is a super-2 number, since 2×231223156631² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 231223156591 and 231223156600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231223156639) 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, 1067120 + ... + 1265381.

It is an arithmetic number, because the mean of its divisors is an integer number (57806397066).

Almost surely, 2^231223156631 is an apocalyptic number.

231223156631 is a deficient number, since it is larger than the sum of its proper divisors (2431633).

231223156631 is an equidigital number, since it uses as much as digits as its factorization.

231223156631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2431632.

The product of its digits is 38880, while the sum is 35.

Adding to 231223156631 its reverse (136651322132), we get a palindrome (367874478763).

The spelling of 231223156631 in words is "two hundred thirty-one billion, two hundred twenty-three million, one hundred fifty-six thousand, six hundred thirty-one".