18304638 has 48 divisors (see below), whose sum is σ = 42389760. Its totient is φ = 5250960.

The previous prime is 18304633. The next prime is 18304639. The reversal of 18304638 is 83640381.

It is a super-2 number, since 2×18304638² = 670119544622088, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 18304599 and 18304608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18304633) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13131 + ... + 14457.

It is an arithmetic number, because the mean of its divisors is an integer number (883120).

Almost surely, 2^18304638 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18304638, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21194880).

18304638 is an abundant number, since it is smaller than the sum of its proper divisors (24085122).

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

18304638 is a wasteful number, since it uses less digits than its factorization.

18304638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1373 (or 1362 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 18304638 is about 4278.3919876514. The cubic root of 18304638 is about 263.5443529237.

The spelling of 18304638 in words is "eighteen million, three hundred four thousand, six hundred thirty-eight".