21866416236 has 84 divisors (see below), whose sum is σ = 65569314832. Its totient is φ = 6247541664.

The previous prime is 21866416219. The next prime is 21866416249. The reversal of 21866416236 is 63261466812.

21866416236 is a `hidden beast` number, since 2 + 18 + 6 + 6 + 4 + 1 + 623 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (84).

It is a junction number, because it is equal to n+sod(n) for n = 21866416191 and 21866416200.

It is an unprimeable number.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 515215 + ... + 556038.

Almost surely, 2^21866416236 is an apocalyptic number.

It is an amenable number.

21866416236 is an abundant number, since it is smaller than the sum of its proper divisors (43702898596).

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

21866416236 is a wasteful number, since it uses less digits than its factorization.

21866416236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1071282 (or 1071265 counting only the distinct ones).

The product of its digits is 497664, while the sum is 45.

The spelling of 21866416236 in words is "twenty-one billion, eight hundred sixty-six million, four hundred sixteen thousand, two hundred thirty-six".