21302031313 has 2 divisors, whose sum is σ = 21302031314. Its totient is φ = 21302031312.

The previous prime is 21302031281. The next prime is 21302031343. The reversal of 21302031313 is 31313020312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16035916689 + 5266114624 = 126633^2 + 72568^2 .

It is a cyclic number.

It is not a de Polignac number, because 21302031313 - 2⁵ = 21302031281 is a prime.

It is not a weakly prime, because it can be changed into another prime (21302031343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10651015656 + 10651015657.

It is an arithmetic number, because the mean of its divisors is an integer number (10651015657).

Almost surely, 2^21302031313 is an apocalyptic number.

It is an amenable number.

21302031313 is a deficient number, since it is larger than the sum of its proper divisors (1).

21302031313 is an equidigital number, since it uses as much as digits as its factorization.

21302031313 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 19.

Adding to 21302031313 its reverse (31313020312), we get a palindrome (52615051625).

The spelling of 21302031313 in words is "twenty-one billion, three hundred two million, thirty-one thousand, three hundred thirteen".