31232131323221 has 4 divisors (see below), whose sum is σ = 31241803711500. Its totient is φ = 31222458934944.

The previous prime is 31232131323199. The next prime is 31232131323229. The reversal of 31232131323221 is 12232313123213.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2792458234225 + 28439673088996 = 1671065^2 + 5332886^2 .

It is a cyclic number.

It is not a de Polignac number, because 31232131323221 - 2²⁶ = 31232064214357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31232131323229) 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, 4836189296 + ... + 4836195753.

It is an arithmetic number, because the mean of its divisors is an integer number (7810450927875).

Almost surely, 2^{31232131323221} is an apocalyptic number.

It is an amenable number.

31232131323221 is a deficient number, since it is larger than the sum of its proper divisors (9672388279).

31232131323221 is an equidigital number, since it uses as much as digits as its factorization.

31232131323221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9672388278.

The product of its digits is 7776, while the sum is 29.

Adding to 31232131323221 its reverse (12232313123213), we get a palindrome (43464444446434).

The spelling of 31232131323221 in words is "thirty-one trillion, two hundred thirty-two billion, one hundred thirty-one million, three hundred twenty-three thousand, two hundred twenty-one".