31320023231 has 16 divisors (see below), whose sum is σ = 36612642816. Its totient is φ = 26233760256.

The previous prime is 31320023173. The next prime is 31320023233. The reversal of 31320023231 is 13232002313.

It is a cyclic number.

It is not a de Polignac number, because 31320023231 - 2¹⁸ = 31319761087 is a prime.

It is a super-2 number, since 2×31320023231² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31320023233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 139295 + ... + 286431.

It is an arithmetic number, because the mean of its divisors is an integer number (2288290176).

Almost surely, 2^31320023231 is an apocalyptic number.

31320023231 is a deficient number, since it is larger than the sum of its proper divisors (5292619585).

31320023231 is a wasteful number, since it uses less digits than its factorization.

31320023231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147838.

The product of its (nonzero) digits is 648, while the sum is 20.

Adding to 31320023231 its reverse (13232002313), we get a palindrome (44552025544).

The spelling of 31320023231 in words is "thirty-one billion, three hundred twenty million, twenty-three thousand, two hundred thirty-one".