18193913640 has 576 divisors, whose sum is σ = 71944104960. Its totient is φ = 3982970880.

The previous prime is 18193913579. The next prime is 18193913707. The reversal of 18193913640 is 4631939181.

18193913640 is a `hidden beast` number, since 18 + 193 + 91 + 364 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 187566072 + ... + 187566168.

It is an arithmetic number, because the mean of its divisors is an integer number (124902960).

Almost surely, 2^18193913640 is an apocalyptic number.

18193913640 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 18193913640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35972052480).

18193913640 is an abundant number, since it is smaller than the sum of its proper divisors (53750191320).

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

18193913640 is an equidigital number, since it uses as much as digits as its factorization.

18193913640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180 (or 145 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 45.

The spelling of 18193913640 in words is "eighteen billion, one hundred ninety-three million, nine hundred thirteen thousand, six hundred forty".