31220023231 has 2 divisors, whose sum is σ = 31220023232. Its totient is φ = 31220023230.

The previous prime is 31220023217. The next prime is 31220023253. The reversal of 31220023231 is 13232002213.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31220023231 - 2⁷ = 31220023103 is a prime.

It is a super-2 number, since 2×31220023231² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31220023199 and 31220023208.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31220020231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15610011615 + 15610011616.

It is an arithmetic number, because the mean of its divisors is an integer number (15610011616).

Almost surely, 2^31220023231 is an apocalyptic number.

31220023231 is a deficient number, since it is larger than the sum of its proper divisors (1).

31220023231 is an equidigital number, since it uses as much as digits as its factorization.

31220023231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 19.

Adding to 31220023231 its reverse (13232002213), we get a palindrome (44452025444).

The spelling of 31220023231 in words is "thirty-one billion, two hundred twenty million, twenty-three thousand, two hundred thirty-one".