31321132231021 has 4 divisors (see below), whose sum is σ = 32401171273500. Its totient is φ = 30241093188544.

The previous prime is 31321132231001. The next prime is 31321132231063. The reversal of 31321132231021 is 12013223112313.

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 9753597455625 + 21567534775396 = 3123075^2 + 4644086^2 .

It is a cyclic number.

It is not a de Polignac number, because 31321132231021 - 2³⁵ = 31286772492653 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 (31321132231001) 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, 540019521196 + ... + 540019521253.

It is an arithmetic number, because the mean of its divisors is an integer number (8100292818375).

Almost surely, 2^{31321132231021} is an apocalyptic number.

It is an amenable number.

31321132231021 is a deficient number, since it is larger than the sum of its proper divisors (1080039042479).

31321132231021 is a wasteful number, since it uses less digits than its factorization.

31321132231021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1080039042478.

The product of its (nonzero) digits is 1296, while the sum is 25.

Adding to 31321132231021 its reverse (12013223112313), we get a palindrome (43334355343334).

The spelling of 31321132231021 in words is "thirty-one trillion, three hundred twenty-one billion, one hundred thirty-two million, two hundred thirty-one thousand, twenty-one".