18383720 has 16 divisors (see below), whose sum is σ = 41363460. Its totient is φ = 7353472.

The previous prime is 18383719. The next prime is 18383741. The reversal of 18383720 is 2738381.

It can be written as a sum of positive squares in 2 ways, for example, as 18369796 + 13924 = 4286^2 + 118^2 .

It is a super-2 number, since 2×18383720² = 675922322076800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 229757 + ... + 229836.

Almost surely, 2^18383720 is an apocalyptic number.

18383720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18383720 is an abundant number, since it is smaller than the sum of its proper divisors (22979740).

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

18383720 is a wasteful number, since it uses less digits than its factorization.

18383720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 459604 (or 459600 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 18383720 is about 4287.6240506835. The cubic root of 18383720 is about 263.9233401538.

The spelling of 18383720 in words is "eighteen million, three hundred eighty-three thousand, seven hundred twenty".