21016731713 has 2 divisors, whose sum is σ = 21016731714. Its totient is φ = 21016731712.

The previous prime is 21016731677. The next prime is 21016731727. The reversal of 21016731713 is 31713761012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20259821569 + 756910144 = 142337^2 + 27512^2 .

It is a cyclic number.

It is not a de Polignac number, because 21016731713 - 2¹⁰ = 21016730689 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21016731713.

It is not a weakly prime, because it can be changed into another prime (21016731793) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10508365856 + 10508365857.

It is an arithmetic number, because the mean of its divisors is an integer number (10508365857).

Almost surely, 2^21016731713 is an apocalyptic number.

It is an amenable number.

21016731713 is a deficient number, since it is larger than the sum of its proper divisors (1).

21016731713 is an equidigital number, since it uses as much as digits as its factorization.

21016731713 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5292, while the sum is 32.

The spelling of 21016731713 in words is "twenty-one billion, sixteen million, seven hundred thirty-one thousand, seven hundred thirteen".