19391888240 has 20 divisors (see below), whose sum is σ = 45086140344. Its totient is φ = 7756755264.

The previous prime is 19391888137. The next prime is 19391888297. The reversal of 19391888240 is 4288819391.

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121199222 + ... + 121199381.

Almost surely, 2^19391888240 is an apocalyptic number.

19391888240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19391888240 is an abundant number, since it is smaller than the sum of its proper divisors (25694252104).

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

19391888240 is a wasteful number, since it uses less digits than its factorization.

19391888240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242398616 (or 242398610 counting only the distinct ones).

The product of its (nonzero) digits is 995328, while the sum is 53.

The spelling of 19391888240 in words is "nineteen billion, three hundred ninety-one million, eight hundred eighty-eight thousand, two hundred forty".