31231022131 has 4 divisors (see below), whose sum is σ = 31232519032. Its totient is φ = 31229525232.

The previous prime is 31231022089. The next prime is 31231022161. The reversal of 31231022131 is 13122013213.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13122013213 = 35069 ⋅374177.

It is a cyclic number.

It is not a de Polignac number, because 31231022131 - 2¹⁷ = 31230891059 is a prime.

It is a super-2 number, since 2×31231022131² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31231022099 and 31231022108.

It is not an unprimeable number, because it can be changed into a prime (31231022161) 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, 716706 + ... + 759031.

It is an arithmetic number, because the mean of its divisors is an integer number (7808129758).

Almost surely, 2^31231022131 is an apocalyptic number.

31231022131 is a deficient number, since it is larger than the sum of its proper divisors (1496901).

31231022131 is a wasteful number, since it uses less digits than its factorization.

31231022131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1496900.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 31231022131 its reverse (13122013213), we get a palindrome (44353035344).

The spelling of 31231022131 in words is "thirty-one billion, two hundred thirty-one million, twenty-two thousand, one hundred thirty-one".