19921079884 has 18 divisors (see below), whose sum is σ = 36443529500. Its totient is φ = 9527471976.

The previous prime is 19921079873. The next prime is 19921079887. The reversal of 19921079884 is 48897012991.

It is not an unprimeable number, because it can be changed into a prime (19921079887) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4705134 + ... + 4709365.

Almost surely, 2^19921079884 is an apocalyptic number.

It is an amenable number.

19921079884 is a deficient number, since it is larger than the sum of its proper divisors (16522449616).

19921079884 is a wasteful number, since it uses less digits than its factorization.

19921079884 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9414549 (or 9414524 counting only the distinct ones).

The product of its (nonzero) digits is 2612736, while the sum is 58.

The spelling of 19921079884 in words is "nineteen billion, nine hundred twenty-one million, seventy-nine thousand, eight hundred eighty-four".