21013031131 has 2 divisors, whose sum is σ = 21013031132. Its totient is φ = 21013031130.

The previous prime is 21013031129. The next prime is 21013031147. The reversal of 21013031131 is 13113031012.

It is an a-pointer prime, because the next prime (21013031147) can be obtained adding 21013031131 to its sum of digits (16).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21013031131 - 2¹ = 21013031129 is a prime.

It is a super-2 number, since 2×21013031131² (a number of 21 digits) contains 22 as substring.

Together with 21013031129, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21013031161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506515565 + 10506515566.

It is an arithmetic number, because the mean of its divisors is an integer number (10506515566).

Almost surely, 2^21013031131 is an apocalyptic number.

21013031131 is a deficient number, since it is larger than the sum of its proper divisors (1).

21013031131 is an equidigital number, since it uses as much as digits as its factorization.

21013031131 is an odious number, because the sum of its binary digits is odd.

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

Adding to 21013031131 its reverse (13113031012), we get a palindrome (34126062143).

The spelling of 21013031131 in words is "twenty-one billion, thirteen million, thirty-one thousand, one hundred thirty-one".