21310051313 has 2 divisors, whose sum is σ = 21310051314. Its totient is φ = 21310051312.

The previous prime is 21310051297. The next prime is 21310051319. The reversal of 21310051313 is 31315001312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15181196944 + 6128854369 = 123212^2 + 78287^2 .

It is a cyclic number.

It is not a de Polignac number, because 21310051313 - 2⁴ = 21310051297 is a prime.

It is not a weakly prime, because it can be changed into another prime (21310051319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655025656 + 10655025657.

It is an arithmetic number, because the mean of its divisors is an integer number (10655025657).

Almost surely, 2^21310051313 is an apocalyptic number.

It is an amenable number.

21310051313 is a deficient number, since it is larger than the sum of its proper divisors (1).

21310051313 is an equidigital number, since it uses as much as digits as its factorization.

21310051313 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 270, while the sum is 20.

Adding to 21310051313 its reverse (31315001312), we get a palindrome (52625052625).

The spelling of 21310051313 in words is "twenty-one billion, three hundred ten million, fifty-one thousand, three hundred thirteen".