21800868815 has 8 divisors (see below), whose sum is σ = 28539319248. Its totient is φ = 15855177280.

The previous prime is 21800868769. The next prime is 21800868821. The reversal of 21800868815 is 51886800812.

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

It is not a de Polignac number, because 21800868815 - 2²² = 21796674511 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21800868815.

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, 198189662 + ... + 198189771.

It is an arithmetic number, because the mean of its divisors is an integer number (3567414906).

Almost surely, 2^21800868815 is an apocalyptic number.

21800868815 is a deficient number, since it is larger than the sum of its proper divisors (6738450433).

21800868815 is a wasteful number, since it uses less digits than its factorization.

21800868815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 396379449.

The product of its (nonzero) digits is 245760, while the sum is 47.

The spelling of 21800868815 in words is "twenty-one billion, eight hundred million, eight hundred sixty-eight thousand, eight hundred fifteen".