21706868479 has 2 divisors, whose sum is σ = 21706868480. Its totient is φ = 21706868478.

The previous prime is 21706868467. The next prime is 21706868509. The reversal of 21706868479 is 97486860712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21706868479 - 2⁹ = 21706867967 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21706868779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10853434239 + 10853434240.

It is an arithmetic number, because the mean of its divisors is an integer number (10853434240).

Almost surely, 2^21706868479 is an apocalyptic number.

21706868479 is a deficient number, since it is larger than the sum of its proper divisors (1).

21706868479 is an equidigital number, since it uses as much as digits as its factorization.

21706868479 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8128512, while the sum is 58.

The spelling of 21706868479 in words is "twenty-one billion, seven hundred six million, eight hundred sixty-eight thousand, four hundred seventy-nine".