21071913659 has 2 divisors, whose sum is σ = 21071913660. Its totient is φ = 21071913658.

The previous prime is 21071913641. The next prime is 21071913679. The reversal of 21071913659 is 95631917012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21071913659 - 2⁸ = 21071913403 is a prime.

It is not a weakly prime, because it can be changed into another prime (21071913679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10535956829 + 10535956830.

It is an arithmetic number, because the mean of its divisors is an integer number (10535956830).

Almost surely, 2^21071913659 is an apocalyptic number.

21071913659 is a deficient number, since it is larger than the sum of its proper divisors (1).

21071913659 is an equidigital number, since it uses as much as digits as its factorization.

21071913659 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 102060, while the sum is 44.

The spelling of 21071913659 in words is "twenty-one billion, seventy-one million, nine hundred thirteen thousand, six hundred fifty-nine".