21786634053 has 18 divisors (see below), whose sum is σ = 33429629714. Its totient is φ = 13670043264.

The previous prime is 21786634021. The next prime is 21786634063. The reversal of 21786634053 is 35043668712.

21786634053 is a `hidden beast` number, since 2 + 1 + 7 + 8 + 6 + 634 + 0 + 5 + 3 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 6320727009 + 15465907044 = 79503^2 + 124362^2 .

It is not a de Polignac number, because 21786634053 - 2⁵ = 21786634021 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21786634003) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 4185526 + ... + 4190727.

Almost surely, 2^21786634053 is an apocalyptic number.

It is an amenable number.

21786634053 is a deficient number, since it is larger than the sum of its proper divisors (11642995661).

21786634053 is a wasteful number, since it uses less digits than its factorization.

21786634053 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8376293 (or 8376273 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 45.

The spelling of 21786634053 in words is "twenty-one billion, seven hundred eighty-six million, six hundred thirty-four thousand, fifty-three".