19638938660 has 48 divisors (see below), whose sum is σ = 45000809280. Its totient is φ = 7139879040.

The previous prime is 19638938647. The next prime is 19638938701. The reversal of 19638938660 is 6683983691.

It is a Smith number, since the sum of its digits (59) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 19638938660.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1638971 + ... + 1650909.

It is an arithmetic number, because the mean of its divisors is an integer number (937516860).

Almost surely, 2^19638938660 is an apocalyptic number.

19638938660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19638938660 is an abundant number, since it is smaller than the sum of its proper divisors (25361870620).

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

19638938660 is a wasteful number, since it uses less digits than its factorization.

19638938660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19436 (or 19434 counting only the distinct ones).

The product of its (nonzero) digits is 10077696, while the sum is 59.

The spelling of 19638938660 in words is "nineteen billion, six hundred thirty-eight million, nine hundred thirty-eight thousand, six hundred sixty".