21206672713 has 2 divisors, whose sum is σ = 21206672714. Its totient is φ = 21206672712.

The previous prime is 21206672689. The next prime is 21206672717. The reversal of 21206672713 is 31727660212.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10608382009 + 10598290704 = 102997^2 + 102948^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21206672713 is a prime.

It is not a weakly prime, because it can be changed into another prime (21206672717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10603336356 + 10603336357.

It is an arithmetic number, because the mean of its divisors is an integer number (10603336357).

Almost surely, 2^21206672713 is an apocalyptic number.

It is an amenable number.

21206672713 is a deficient number, since it is larger than the sum of its proper divisors (1).

21206672713 is an equidigital number, since it uses as much as digits as its factorization.

21206672713 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 42336, while the sum is 37.

The spelling of 21206672713 in words is "twenty-one billion, two hundred six million, six hundred seventy-two thousand, seven hundred thirteen".