31220402231 has 2 divisors, whose sum is σ = 31220402232. Its totient is φ = 31220402230.

The previous prime is 31220402189. The next prime is 31220402243. The reversal of 31220402231 is 13220402213.

It is a strong prime.

It is an emirp because it is prime and its reverse (13220402213) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31220402231 - 2⁶ = 31220402167 is a prime.

It is a super-2 number, since 2×31220402231² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31220405231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15610201115 + 15610201116.

It is an arithmetic number, because the mean of its divisors is an integer number (15610201116).

Almost surely, 2^31220402231 is an apocalyptic number.

31220402231 is a deficient number, since it is larger than the sum of its proper divisors (1).

31220402231 is an equidigital number, since it uses as much as digits as its factorization.

31220402231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 31220402231 its reverse (13220402213), we get a palindrome (44440804444).

The spelling of 31220402231 in words is "thirty-one billion, two hundred twenty million, four hundred two thousand, two hundred thirty-one".