19991904975 has 192 divisors, whose sum is σ = 44730470400. Its totient is φ = 8550645120.

The previous prime is 19991904949. The next prime is 19991904983. The reversal of 19991904975 is 57940919991.

It is not a de Polignac number, because 19991904975 - 2⁸ = 19991904719 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 7449984 + ... + 7452666.

It is an arithmetic number, because the mean of its divisors is an integer number (232971200).

Almost surely, 2^19991904975 is an apocalyptic number.

19991904975 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

19991904975 is an abundant number, since it is smaller than the sum of its proper divisors (24738565425).

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

19991904975 is a wasteful number, since it uses less digits than its factorization.

19991904975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2811 (or 2800 counting only the distinct ones).

The product of its (nonzero) digits is 8266860, while the sum is 63.

The spelling of 19991904975 in words is "nineteen billion, nine hundred ninety-one million, nine hundred four thousand, nine hundred seventy-five".