20644863178 has 16 divisors (see below), whose sum is σ = 31395012480. Its totient is φ = 10180156896.

The previous prime is 20644863167. The next prime is 20644863203. The reversal of 20644863178 is 87136844602.

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, 65526 + ... + 213502.

It is an arithmetic number, because the mean of its divisors is an integer number (1962188280).

Almost surely, 2^20644863178 is an apocalyptic number.

20644863178 is a deficient number, since it is larger than the sum of its proper divisors (10750149302).

20644863178 is a wasteful number, since it uses less digits than its factorization.

20644863178 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148941.

The product of its (nonzero) digits is 1548288, while the sum is 49.

The spelling of 20644863178 in words is "twenty billion, six hundred forty-four million, eight hundred sixty-three thousand, one hundred seventy-eight".