18939795840 has 1280 divisors, whose sum is σ = 84597004800. Its totient is φ = 3941498880.

The previous prime is 18939795779. The next prime is 18939795883. The reversal of 18939795840 is 4859793981.

18939795840 is a `hidden beast` number, since 1 + 89 + 397 + 95 + 84 + 0 = 666.

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 159 ways as a sum of consecutive naturals, for example, 282683487 + ... + 282683553.

It is an arithmetic number, because the mean of its divisors is an integer number (66091410).

Almost surely, 2^18939795840 is an apocalyptic number.

18939795840 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 18939795840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42298502400).

18939795840 is an abundant number, since it is smaller than the sum of its proper divisors (65657208960).

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

18939795840 is a wasteful number, since it uses less digits than its factorization.

18939795840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165 (or 144 counting only the distinct ones).

The product of its (nonzero) digits is 19595520, while the sum is 63.

The spelling of 18939795840 in words is "eighteen billion, nine hundred thirty-nine million, seven hundred ninety-five thousand, eight hundred forty".