18561444 has 24 divisors (see below), whose sum is σ = 47247648. Its totient is φ = 5624640.

The previous prime is 18561443. The next prime is 18561503. The reversal of 18561444 is 44416581.

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

It is not an unprimeable number, because it can be changed into a prime (18561443) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70177 + ... + 70440.

It is an arithmetic number, because the mean of its divisors is an integer number (1968652).

Almost surely, 2^18561444 is an apocalyptic number.

It is an amenable number.

18561444 is an abundant number, since it is smaller than the sum of its proper divisors (28686204).

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

18561444 is a wasteful number, since it uses less digits than its factorization.

18561444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140635 (or 140633 counting only the distinct ones).

The product of its digits is 15360, while the sum is 33.

The square root of 18561444 is about 4308.2994324907. The cubic root of 18561444 is about 264.7711041144.

The spelling of 18561444 in words is "eighteen million, five hundred sixty-one thousand, four hundred forty-four".