18613616640 has 480 divisors, whose sum is σ = 64548368640. Its totient is φ = 4567597056.

The previous prime is 18613616633. The next prime is 18613616683. The reversal of 18613616640 is 4661631681.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (480).

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 18613616592 and 18613616601.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 209141716 + ... + 209141804.

It is an arithmetic number, because the mean of its divisors is an integer number (134475768).

Almost surely, 2^18613616640 is an apocalyptic number.

18613616640 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 18613616640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32274184320).

18613616640 is an abundant number, since it is smaller than the sum of its proper divisors (45934752000).

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

18613616640 is an equidigital number, since it uses as much as digits as its factorization.

18613616640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185 (or 159 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 42.

The spelling of 18613616640 in words is "eighteen billion, six hundred thirteen million, six hundred sixteen thousand, six hundred forty".