31321234721 has 32 divisors (see below), whose sum is σ = 36661248000. Its totient is φ = 26206407360.

The previous prime is 31321234669. The next prime is 31321234751. The reversal of 31321234721 is 12743212313.

It is a de Polignac number, because none of the positive numbers 2^k-31321234721 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (31321234751) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 35470946 + ... + 35471828.

It is an arithmetic number, because the mean of its divisors is an integer number (1145664000).

Almost surely, 2^31321234721 is an apocalyptic number.

It is an amenable number.

31321234721 is a deficient number, since it is larger than the sum of its proper divisors (5340013279).

31321234721 is a wasteful number, since it uses less digits than its factorization.

31321234721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1589.

The product of its digits is 6048, while the sum is 29.

The spelling of 31321234721 in words is "thirty-one billion, three hundred twenty-one million, two hundred thirty-four thousand, seven hundred twenty-one".