19866109256 has 16 divisors (see below), whose sum is σ = 42570234240. Its totient is φ = 8514046800.

The previous prime is 19866109157. The next prime is 19866109261. The reversal of 19866109256 is 65290166891.

It is a happy number.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 19866109198 and 19866109207.

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, 177375920 + ... + 177376031.

It is an arithmetic number, because the mean of its divisors is an integer number (2660639640).

Almost surely, 2^19866109256 is an apocalyptic number.

It is an amenable number.

19866109256 is an abundant number, since it is smaller than the sum of its proper divisors (22704124984).

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

19866109256 is a wasteful number, since it uses less digits than its factorization.

19866109256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 354751964 (or 354751960 counting only the distinct ones).

The product of its (nonzero) digits is 1399680, while the sum is 53.

The spelling of 19866109256 in words is "nineteen billion, eight hundred sixty-six million, one hundred nine thousand, two hundred fifty-six".