18404720 has 20 divisors (see below), whose sum is σ = 42791160. Its totient is φ = 7361856.

The previous prime is 18404719. The next prime is 18404723. The reversal of 18404720 is 2740481.

It is a tau number, because it is divible by the number of its divisors (20).

It is a hoax number, since the sum of its digits (26) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 18404720.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18404723) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 114950 + ... + 115109.

It is an arithmetic number, because the mean of its divisors is an integer number (2139558).

Almost surely, 2^18404720 is an apocalyptic number.

18404720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18404720 is an abundant number, since it is smaller than the sum of its proper divisors (24386440).

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

18404720 is a wasteful number, since it uses less digits than its factorization.

18404720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 230072 (or 230066 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 26.

The square root of 18404720 is about 4290.0722604637. The cubic root of 18404720 is about 264.0237964470.

The spelling of 18404720 in words is "eighteen million, four hundred four thousand, seven hundred twenty".