31221013031 has 16 divisors (see below), whose sum is σ = 35266084224. Its totient is φ = 27443867904.

The previous prime is 31221013007. The next prime is 31221013069. The reversal of 31221013031 is 13031012213.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31221013031 is a prime.

It is a super-2 number, since 2×31221013031² (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 (31221013081) 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, 667910 + ... + 713123.

It is an arithmetic number, because the mean of its divisors is an integer number (2204130264).

Almost surely, 2^31221013031 is an apocalyptic number.

31221013031 is a deficient number, since it is larger than the sum of its proper divisors (4045071193).

31221013031 is a wasteful number, since it uses less digits than its factorization.

31221013031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1381130.

The product of its (nonzero) digits is 108, while the sum is 17.

Adding to 31221013031 its reverse (13031012213), we get a palindrome (44252025244).

The spelling of 31221013031 in words is "thirty-one billion, two hundred twenty-one million, thirteen thousand, thirty-one".