21031013131 has 2 divisors, whose sum is σ = 21031013132. Its totient is φ = 21031013130.

The previous prime is 21031013093. The next prime is 21031013137. The reversal of 21031013131 is 13131013012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21031013131 - 2²¹ = 21028915979 is a prime.

It is a super-2 number, since 2×21031013131² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21031013137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10515506565 + 10515506566.

It is an arithmetic number, because the mean of its divisors is an integer number (10515506566).

Almost surely, 2^21031013131 is an apocalyptic number.

21031013131 is a deficient number, since it is larger than the sum of its proper divisors (1).

21031013131 is an equidigital number, since it uses as much as digits as its factorization.

21031013131 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54, while the sum is 16.

Adding to 21031013131 its reverse (13131013012), we get a palindrome (34162026143).

The spelling of 21031013131 in words is "twenty-one billion, thirty-one million, thirteen thousand, one hundred thirty-one".