31121001321 has 4 divisors (see below), whose sum is σ = 41494668432. Its totient is φ = 20747334212.

The previous prime is 31121001311. The next prime is 31121001347. The reversal of 31121001321 is 12310012113.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 31121001321 - 2²⁵ = 31087446889 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31121001321.

It is not an unprimeable number, because it can be changed into a prime (31121001311) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5186833551 + ... + 5186833556.

It is an arithmetic number, because the mean of its divisors is an integer number (10373667108).

Almost surely, 2^31121001321 is an apocalyptic number.

It is an amenable number.

31121001321 is a deficient number, since it is larger than the sum of its proper divisors (10373667111).

31121001321 is a wasteful number, since it uses less digits than its factorization.

31121001321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10373667110.

The product of its (nonzero) digits is 36, while the sum is 15.

Adding to 31121001321 its reverse (12310012113), we get a palindrome (43431013434).

The spelling of 31121001321 in words is "thirty-one billion, one hundred twenty-one million, one thousand, three hundred twenty-one".