18704640 has 72 divisors (see below), whose sum is σ = 59750208. Its totient is φ = 4986880.

The previous prime is 18704639. The next prime is 18704657. The reversal of 18704640 is 4640781.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 18704598 and 18704607.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1405 + ... + 6275.

It is an arithmetic number, because the mean of its divisors is an integer number (829864).

Almost surely, 2^18704640 is an apocalyptic number.

18704640 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 18704640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29875104).

18704640 is an abundant number, since it is smaller than the sum of its proper divisors (41045568).

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

18704640 is an equidigital number, since it uses as much as digits as its factorization.

18704640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4895 (or 4881 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 18704640 is about 4324.8861256685. The cubic root of 18704640 is about 265.4502373389.

The spelling of 18704640 in words is "eighteen million, seven hundred four thousand, six hundred forty".