21310213291 has 2 divisors, whose sum is σ = 21310213292. Its totient is φ = 21310213290.

The previous prime is 21310213283. The next prime is 21310213313. The reversal of 21310213291 is 19231201312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21310213291 - 2³ = 21310213283 is a prime.

It is not a weakly prime, because it can be changed into another prime (21310213241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655106645 + 10655106646.

It is an arithmetic number, because the mean of its divisors is an integer number (10655106646).

Almost surely, 2^21310213291 is an apocalyptic number.

21310213291 is a deficient number, since it is larger than the sum of its proper divisors (1).

21310213291 is an equidigital number, since it uses as much as digits as its factorization.

21310213291 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 25.

It can be divided in two parts, 2131021 and 3291, that added together give a palindrome (2134312).

The spelling of 21310213291 in words is "twenty-one billion, three hundred ten million, two hundred thirteen thousand, two hundred ninety-one".