31212130331021 has 32 divisors (see below), whose sum is σ = 33085830260736. Its totient is φ = 29383005960000.

The previous prime is 31212130331017. The next prime is 31212130331071. The reversal of 31212130331021 is 12013303121213.

It is a cyclic number.

It is not a de Polignac number, because 31212130331021 - 2² = 31212130331017 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31212130331071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2506790846 + ... + 2506803296.

It is an arithmetic number, because the mean of its divisors is an integer number (1033932195648).

Almost surely, 2^{31212130331021} is an apocalyptic number.

It is an amenable number.

31212130331021 is a deficient number, since it is larger than the sum of its proper divisors (1873699929715).

31212130331021 is a wasteful number, since it uses less digits than its factorization.

31212130331021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15113.

The product of its (nonzero) digits is 648, while the sum is 23.

Adding to 31212130331021 its reverse (12013303121213), we get a palindrome (43225433452234).

The spelling of 31212130331021 in words is "thirty-one trillion, two hundred twelve billion, one hundred thirty million, three hundred thirty-one thousand, twenty-one".