18909398780 has 96 divisors (see below), whose sum is σ = 41353804800. Its totient is φ = 7257696768.

The previous prime is 18909398743. The next prime is 18909398789. The reversal of 18909398780 is 8789390981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18909398789) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 22537601 + ... + 22538439.

It is an arithmetic number, because the mean of its divisors is an integer number (430768800).

Almost surely, 2^18909398780 is an apocalyptic number.

18909398780 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 18909398780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20676902400).

18909398780 is an abundant number, since it is smaller than the sum of its proper divisors (22444406020).

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

18909398780 is a wasteful number, since it uses less digits than its factorization.

18909398780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1323 (or 1321 counting only the distinct ones).

The product of its (nonzero) digits is 7838208, while the sum is 62.

The spelling of 18909398780 in words is "eighteen billion, nine hundred nine million, three hundred ninety-eight thousand, seven hundred eighty".