19998001872 has 120 divisors (see below), whose sum is σ = 58285019520. Its totient is φ = 6637800960.

The previous prime is 19998001871. The next prime is 19998001879. The reversal of 19998001872 is 27810089991.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19998001871) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 918472 + ... + 939992.

It is an arithmetic number, because the mean of its divisors is an integer number (485708496).

Almost surely, 2^19998001872 is an apocalyptic number.

19998001872 is a gapful number since it is divisible by the number (12) 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 19998001872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29142509760).

19998001872 is an abundant number, since it is smaller than the sum of its proper divisors (38287017648).

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

19998001872 is a wasteful number, since it uses less digits than its factorization.

19998001872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21783 (or 21765 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 54.

The spelling of 19998001872 in words is "nineteen billion, nine hundred ninety-eight million, one thousand, eight hundred seventy-two".