20636440168 has 16 divisors (see below), whose sum is σ = 38833016580. Its totient is φ = 10280969088.

The previous prime is 20636440141. The next prime is 20636440183. The reversal of 20636440168 is 86104463602.

It can be written as a sum of positive squares in 2 ways, for example, as 18801345924 + 1835094244 = 137118^2 + 42838^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20636440168.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4654021 + ... + 4658452.

Almost surely, 2^20636440168 is an apocalyptic number.

It is an amenable number.

20636440168 is a deficient number, since it is larger than the sum of its proper divisors (18196576412).

20636440168 is a wasteful number, since it uses less digits than its factorization.

20636440168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9312756 (or 9312752 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 40.

The spelling of 20636440168 in words is "twenty billion, six hundred thirty-six million, four hundred forty thousand, one hundred sixty-eight".