21709642063 has 8 divisors (see below), whose sum is σ = 23434696800. Its totient is φ = 20049683808.

The previous prime is 21709642037. The next prime is 21709642069. The reversal of 21709642063 is 36024690712.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21709642063 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21709642069) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16273428 + ... + 16274761.

It is an arithmetic number, because the mean of its divisors is an integer number (2929337100).

Almost surely, 2^21709642063 is an apocalyptic number.

21709642063 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21709642063 is a deficient number, since it is larger than the sum of its proper divisors (1725054737).

21709642063 is a wasteful number, since it uses less digits than its factorization.

21709642063 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32548241.

The product of its (nonzero) digits is 108864, while the sum is 40.

The spelling of 21709642063 in words is "twenty-one billion, seven hundred nine million, six hundred forty-two thousand, sixty-three".