18404521380 has 384 divisors, whose sum is σ = 69543936000. Its totient is φ = 3947097600.

The previous prime is 18404521379. The next prime is 18404521391. The reversal of 18404521380 is 8312540481.

18404521380 is a `hidden beast` number, since 18 + 40 + 4 + 521 + 3 + 80 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 7827205 + ... + 7829555.

It is an arithmetic number, because the mean of its divisors is an integer number (181104000).

Almost surely, 2^18404521380 is an apocalyptic number.

18404521380 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 18404521380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34771968000).

18404521380 is an abundant number, since it is smaller than the sum of its proper divisors (51139414620).

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

18404521380 is a wasteful number, since it uses less digits than its factorization.

18404521380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2504 (or 2496 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 36.

The spelling of 18404521380 in words is "eighteen billion, four hundred four million, five hundred twenty-one thousand, three hundred eighty".