18634478353920 has 3200 divisors, whose sum is σ = 83009157073920. Its totient is φ = 3930988216320.

The previous prime is 18634478353901. The next prime is 18634478353961. The reversal of 18634478353920 is 2935387443681.

It is a happy number.

18634478353920 is a `hidden beast` number, since 1 + 8 + 6 + 3 + 4 + 4 + 78 + 3 + 539 + 20 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 319 ways as a sum of consecutive naturals, for example, 60698626407 + ... + 60698626713.

It is a 1-persistent number, because it is pandigital, but 2⋅18634478353920 = 37268956707840 is not.

Almost surely, 2^{18634478353920} is an apocalyptic number.

18634478353920 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 18634478353920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41504578536960).

18634478353920 is an abundant number, since it is smaller than the sum of its proper divisors (64374678720000).

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

18634478353920 is a wasteful number, since it uses less digits than its factorization.

18634478353920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478 (or 453 counting only the distinct ones).

The product of its (nonzero) digits is 104509440, while the sum is 63.

The spelling of 18634478353920 in words is "eighteen trillion, six hundred thirty-four billion, four hundred seventy-eight million, three hundred fifty-three thousand, nine hundred twenty".