18445440 has 128 divisors (see below), whose sum is σ = 63403200. Its totient is φ = 4534272.

The previous prime is 18445429. The next prime is 18445451. The reversal of 18445440 is 4454481.

It is an interprime number because it is at equal distance from previous prime (18445429) and next prime (18445451).

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 18445398 and 18445407.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24591 + ... + 25329.

Almost surely, 2^18445440 is an apocalyptic number.

18445440 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 18445440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31701600).

18445440 is an abundant number, since it is smaller than the sum of its proper divisors (44957760).

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

18445440 is a wasteful number, since it uses less digits than its factorization.

18445440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 774 (or 762 counting only the distinct ones).

The product of its (nonzero) digits is 10240, while the sum is 30.

The square root of 18445440 is about 4294.8154791562. The cubic root of 18445440 is about 264.2183684537.

The spelling of 18445440 in words is "eighteen million, four hundred forty-five thousand, four hundred forty".