21313430951 has 2 divisors, whose sum is σ = 21313430952. Its totient is φ = 21313430950.

The previous prime is 21313430923. The next prime is 21313431059. The reversal of 21313430951 is 15903431312.

Together with next prime (21313431059) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21313430951 - 2¹⁴ = 21313414567 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21313430921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10656715475 + 10656715476.

It is an arithmetic number, because the mean of its divisors is an integer number (10656715476).

Almost surely, 2^21313430951 is an apocalyptic number.

21313430951 is a deficient number, since it is larger than the sum of its proper divisors (1).

21313430951 is an equidigital number, since it uses as much as digits as its factorization.

21313430951 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9720, while the sum is 32.

The spelling of 21313430951 in words is "twenty-one billion, three hundred thirteen million, four hundred thirty thousand, nine hundred fifty-one".