31231221332129 has 24 divisors (see below), whose sum is σ = 39129160472640. Its totient is φ = 24707679774624.

The previous prime is 31231221332117. The next prime is 31231221332131. The reversal of 31231221332129 is 92123312213213.

It is a de Polignac number, because none of the positive numbers 2^k-31231221332129 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31231221332929) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3049532 + ... + 8471250.

It is an arithmetic number, because the mean of its divisors is an integer number (1630381686360).

Almost surely, 2^{31231221332129} is an apocalyptic number.

It is an amenable number.

31231221332129 is a deficient number, since it is larger than the sum of its proper divisors (7897939140511).

31231221332129 is a wasteful number, since it uses less digits than its factorization.

31231221332129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5430789 (or 5430782 counting only the distinct ones).

The product of its digits is 23328, while the sum is 35.

The spelling of 31231221332129 in words is "thirty-one trillion, two hundred thirty-one billion, two hundred twenty-one million, three hundred thirty-two thousand, one hundred twenty-nine".