21002321313 has 6 divisors (see below), whose sum is σ = 30336686354. Its totient is φ = 14001547536.

The previous prime is 21002321309. The next prime is 21002321321. The reversal of 21002321313 is 31312320012.

It can be written as a sum of positive squares in only one way, i.e., 13472941329 + 7529379984 = 116073^2 + 86772^2 .

It is not a de Polignac number, because 21002321313 - 2² = 21002321309 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21002321393) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1166795620 + ... + 1166795637.

Almost surely, 2^21002321313 is an apocalyptic number.

It is an amenable number.

21002321313 is a deficient number, since it is larger than the sum of its proper divisors (9334365041).

21002321313 is a wasteful number, since it uses less digits than its factorization.

21002321313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2333591263 (or 2333591260 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21002321313 its reverse (31312320012), we get a palindrome (52314641325).

The spelling of 21002321313 in words is "twenty-one billion, two million, three hundred twenty-one thousand, three hundred thirteen".