21799803816 has 48 divisors (see below), whose sum is σ = 67475584800. Its totient is φ = 6228515232.

The previous prime is 21799803803. The next prime is 21799803863. The reversal of 21799803816 is 61830899712.

21799803816 is a `hidden beast` number, since 2 + 179 + 98 + 0 + 381 + 6 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21626286 + ... + 21627293.

It is an arithmetic number, because the mean of its divisors is an integer number (1405741350).

Almost surely, 2^21799803816 is an apocalyptic number.

It is an amenable number.

21799803816 is an abundant number, since it is smaller than the sum of its proper divisors (45675780984).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21799803816 is a wasteful number, since it uses less digits than its factorization.

21799803816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43253598 (or 43253591 counting only the distinct ones).

The product of its (nonzero) digits is 1306368, while the sum is 54.

The spelling of 21799803816 in words is "twenty-one billion, seven hundred ninety-nine million, eight hundred three thousand, eight hundred sixteen".