21766339805 has 8 divisors (see below), whose sum is σ = 29850980352. Its totient is φ = 14925490128.

The previous prime is 21766339723. The next prime is 21766339843. The reversal of 21766339805 is 50893366712.

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-21766339805 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 310947677 + ... + 310947746.

It is an arithmetic number, because the mean of its divisors is an integer number (3731372544).

Almost surely, 2^21766339805 is an apocalyptic number.

It is an amenable number.

21766339805 is a deficient number, since it is larger than the sum of its proper divisors (8084640547).

21766339805 is an equidigital number, since it uses as much as digits as its factorization.

21766339805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 621895435.

The product of its (nonzero) digits is 1632960, while the sum is 50.

The spelling of 21766339805 in words is "twenty-one billion, seven hundred sixty-six million, three hundred thirty-nine thousand, eight hundred five".