31201023221 has 24 divisors (see below), whose sum is σ = 33164910720. Its totient is φ = 29297448576.

The previous prime is 31201023187. The next prime is 31201023229. The reversal of 31201023221 is 12232010213.

It is a de Polignac number, because none of the positive numbers 2^k-31201023221 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31201023221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31201023229) 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, 33950600 + ... + 33951518.

It is an arithmetic number, because the mean of its divisors is an integer number (1381871280).

Almost surely, 2^31201023221 is an apocalyptic number.

It is an amenable number.

31201023221 is a deficient number, since it is larger than the sum of its proper divisors (1963887499).

31201023221 is an equidigital number, since it uses as much as digits as its factorization.

31201023221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1365 (or 1292 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 31201023221 its reverse (12232010213), we get a palindrome (43433033434).

The spelling of 31201023221 in words is "thirty-one billion, two hundred one million, twenty-three thousand, two hundred twenty-one".