18359440 has 80 divisors (see below), whose sum is σ = 48139776. Its totient is φ = 6451200.

The previous prime is 18359417. The next prime is 18359447. The reversal of 18359440 is 4495381.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×18359440² = 674138074227200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18359396 and 18359405.

It is not an unprimeable number, because it can be changed into a prime (18359447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26944 + ... + 27616.

Almost surely, 2^18359440 is an apocalyptic number.

18359440 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 18359440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24069888).

18359440 is an abundant number, since it is smaller than the sum of its proper divisors (29780336).

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

18359440 is a wasteful number, since it uses less digits than its factorization.

18359440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 728 (or 722 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 18359440 is about 4284.7917102235. The cubic root of 18359440 is about 263.8070981403.

The spelling of 18359440 in words is "eighteen million, three hundred fifty-nine thousand, four hundred forty".