19971878900 has 36 divisors (see below), whose sum is σ = 44346869952. Its totient is φ = 7802964960.

The previous prime is 19971878897. The next prime is 19971878939. The reversal of 19971878900 is 987817991.

It is a self number, because there is not a number n which added to its sum of digits gives 19971878900.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2318012 + ... + 2326611.

Almost surely, 2^19971878900 is an apocalyptic number.

19971878900 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19971878900 is an abundant number, since it is smaller than the sum of its proper divisors (24374991052).

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

19971878900 is a wasteful number, since it uses less digits than its factorization.

19971878900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4644680 (or 4644673 counting only the distinct ones).

The product of its (nonzero) digits is 2286144, while the sum is 59.

The spelling of 19971878900 in words is "nineteen billion, nine hundred seventy-one million, eight hundred seventy-eight thousand, nine hundred".