18864720 has 240 divisors, whose sum is σ = 76602240. Its totient is φ = 4064256.

The previous prime is 18864691. The next prime is 18864731. The reversal of 18864720 is 2746881.

18864720 is a `hidden beast` number, since 1 + 8 + 8 + 647 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 95662 + ... + 95858.

It is an arithmetic number, because the mean of its divisors is an integer number (319176).

Almost surely, 2^18864720 is an apocalyptic number.

18864720 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 18864720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38301120).

18864720 is an abundant number, since it is smaller than the sum of its proper divisors (57737520).

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

18864720 is a wasteful number, since it uses less digits than its factorization.

18864720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242 (or 233 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 18864720 is about 4343.3535430586. The cubic root of 18864720 is about 266.2053552070.

The spelling of 18864720 in words is "eighteen million, eight hundred sixty-four thousand, seven hundred twenty".