21002807713 has 2 divisors, whose sum is σ = 21002807714. Its totient is φ = 21002807712.

The previous prime is 21002807671. The next prime is 21002807729. The reversal of 21002807713 is 31770820012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19190006784 + 1812800929 = 138528^2 + 42577^2 .

It is a cyclic number.

It is not a de Polignac number, because 21002807713 - 2²⁵ = 20969253281 is a prime.

It is a super-2 number, since 2×21002807713² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21002867713) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501403856 + 10501403857.

It is an arithmetic number, because the mean of its divisors is an integer number (10501403857).

Almost surely, 2^21002807713 is an apocalyptic number.

It is an amenable number.

21002807713 is a deficient number, since it is larger than the sum of its proper divisors (1).

21002807713 is an equidigital number, since it uses as much as digits as its factorization.

21002807713 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4704, while the sum is 31.

The spelling of 21002807713 in words is "twenty-one billion, two million, eight hundred seven thousand, seven hundred thirteen".