31321203131 has 4 divisors (see below), whose sum is σ = 31469645064. Its totient is φ = 31172761200.

The previous prime is 31321203071. The next prime is 31321203149. The reversal of 31321203131 is 13130212313.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13130212313 = 173 ⋅75897181.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31321203131 is a prime.

It is a super-2 number, since 2×31321203131² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31321203161) 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, 74220650 + ... + 74221071.

It is an arithmetic number, because the mean of its divisors is an integer number (7867411266).

Almost surely, 2^31321203131 is an apocalyptic number.

31321203131 is a deficient number, since it is larger than the sum of its proper divisors (148441933).

31321203131 is a wasteful number, since it uses less digits than its factorization.

31321203131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148441932.

The product of its (nonzero) digits is 324, while the sum is 20.

Adding to 31321203131 its reverse (13130212313), we get a palindrome (44451415444).

The spelling of 31321203131 in words is "thirty-one billion, three hundred twenty-one million, two hundred three thousand, one hundred thirty-one".