19998239040 has 672 divisors, whose sum is σ = 78160083456. Its totient is φ = 4837294080.

The previous prime is 19998238999. The next prime is 19998239059. The reversal of 19998239040 is 4093289991.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 73794105 + ... + 73794375.

It is an arithmetic number, because the mean of its divisors is an integer number (116309648).

Almost surely, 2^19998239040 is an apocalyptic number.

19998239040 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 19998239040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39080041728).

19998239040 is an abundant number, since it is smaller than the sum of its proper divisors (58161844416).

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

19998239040 is a wasteful number, since it uses less digits than its factorization.

19998239040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 389 (or 367 counting only the distinct ones).

The product of its (nonzero) digits is 1259712, while the sum is 54.

The spelling of 19998239040 in words is "nineteen billion, nine hundred ninety-eight million, two hundred thirty-nine thousand, forty".