21684718105 has 8 divisors (see below), whose sum is σ = 26462707200. Its totient is φ = 17053744176.

The previous prime is 21684718087. The next prime is 21684718141. The reversal of 21684718105 is 50181748612.

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

It is a cyclic number.

It is not a de Polignac number, because 21684718105 - 2¹¹ = 21684716057 is a prime.

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, 36753465 + ... + 36754054.

It is an arithmetic number, because the mean of its divisors is an integer number (3307838400).

Almost surely, 2^21684718105 is an apocalyptic number.

It is an amenable number.

21684718105 is a deficient number, since it is larger than the sum of its proper divisors (4777989095).

21684718105 is an equidigital number, since it uses as much as digits as its factorization.

21684718105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73507583.

The product of its (nonzero) digits is 107520, while the sum is 43.

The spelling of 21684718105 in words is "twenty-one billion, six hundred eighty-four million, seven hundred eighteen thousand, one hundred five".