19999742844 has 48 divisors (see below), whose sum is σ = 46864611360. Its totient is φ = 6638257920.

The previous prime is 19999742809. The next prime is 19999742909. The reversal of 19999742844 is 44824799991.

It is a happy number.

It is a super-2 number, since 2×19999742844² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8370402 + ... + 8372790.

It is an arithmetic number, because the mean of its divisors is an integer number (976346070).

Almost surely, 2^19999742844 is an apocalyptic number.

It is an amenable number.

19999742844 is an abundant number, since it is smaller than the sum of its proper divisors (26864868516).

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

19999742844 is a wasteful number, since it uses less digits than its factorization.

19999742844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5070 (or 5068 counting only the distinct ones).

The product of its digits is 47029248, while the sum is 66.

The spelling of 19999742844 in words is "nineteen billion, nine hundred ninety-nine million, seven hundred forty-two thousand, eight hundred forty-four".