21168130931 has 2 divisors, whose sum is σ = 21168130932. Its totient is φ = 21168130930.

The previous prime is 21168130909. The next prime is 21168130961. The reversal of 21168130931 is 13903186112.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21168130931 is a prime.

It is a super-2 number, since 2×21168130931² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21168130891 and 21168130900.

It is not a weakly prime, because it can be changed into another prime (21168130901) 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, 10584065465 + 10584065466.

It is an arithmetic number, because the mean of its divisors is an integer number (10584065466).

Almost surely, 2^21168130931 is an apocalyptic number.

21168130931 is a deficient number, since it is larger than the sum of its proper divisors (1).

21168130931 is an equidigital number, since it uses as much as digits as its factorization.

21168130931 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 35.

The spelling of 21168130931 in words is "twenty-one billion, one hundred sixty-eight million, one hundred thirty thousand, nine hundred thirty-one".