21716713 has 2 divisors, whose sum is σ = 21716714. Its totient is φ = 21716712.

The previous prime is 21716693. The next prime is 21716729. The reversal of 21716713 is 31761712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16999129 + 4717584 = 4123^2 + 2172^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21716713 is a prime.

It is not a weakly prime, because it can be changed into another prime (21716413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10858356 + 10858357.

It is an arithmetic number, because the mean of its divisors is an integer number (10858357).

Almost surely, 2^21716713 is an apocalyptic number.

It is an amenable number.

21716713 is a deficient number, since it is larger than the sum of its proper divisors (1).

21716713 is an equidigital number, since it uses as much as digits as its factorization.

21716713 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1764, while the sum is 28.

The square root of 21716713 is about 4660.1194190707. The cubic root of 21716713 is about 278.9960345955.

The spelling of 21716713 in words is "twenty-one million, seven hundred sixteen thousand, seven hundred thirteen".