20131331291 has 2 divisors, whose sum is σ = 20131331292. Its totient is φ = 20131331290.

The previous prime is 20131331261. The next prime is 20131331327. The reversal of 20131331291 is 19213313102.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20131331291 - 2²⁶ = 20064222427 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20131331291.

It is not a weakly prime, because it can be changed into another prime (20131331261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10065665645 + 10065665646.

It is an arithmetic number, because the mean of its divisors is an integer number (10065665646).

Almost surely, 2^20131331291 is an apocalyptic number.

20131331291 is a deficient number, since it is larger than the sum of its proper divisors (1).

20131331291 is an equidigital number, since it uses as much as digits as its factorization.

20131331291 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 972, while the sum is 26.

Adding to 20131331291 its reverse (19213313102), we get a palindrome (39344644393).

The spelling of 20131331291 in words is "twenty billion, one hundred thirty-one million, three hundred thirty-one thousand, two hundred ninety-one".