19910927920 has 120 divisors (see below), whose sum is σ = 50291874864. Its totient is φ = 7287694848.

The previous prime is 19910927917. The next prime is 19910927957. The reversal of 19910927920 is 2972901991.

It is a happy number.

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 23 ways as a sum of consecutive naturals, for example, 16773567 + ... + 16774753.

Almost surely, 2^19910927920 is an apocalyptic number.

19910927920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19910927920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25145937432).

19910927920 is an abundant number, since it is smaller than the sum of its proper divisors (30380946944).

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

19910927920 is a wasteful number, since it uses less digits than its factorization.

19910927920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1467 (or 1334 counting only the distinct ones).

The product of its (nonzero) digits is 183708, while the sum is 49.

The spelling of 19910927920 in words is "nineteen billion, nine hundred ten million, nine hundred twenty-seven thousand, nine hundred twenty".