18408444 has 24 divisors (see below), whose sum is σ = 43037568. Its totient is φ = 6124080.

The previous prime is 18408431. The next prime is 18408457. The reversal of 18408444 is 44480481.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18408431) and next prime (18408457).

It is a super-2 number, since 2×18408444² = 677741621002272, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6579 + ... + 8949.

It is an arithmetic number, because the mean of its divisors is an integer number (1793232).

Almost surely, 2^18408444 is an apocalyptic number.

It is an amenable number.

18408444 is an abundant number, since it is smaller than the sum of its proper divisors (24629124).

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

18408444 is a wasteful number, since it uses less digits than its factorization.

18408444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3025 (or 3023 counting only the distinct ones).

The product of its (nonzero) digits is 16384, while the sum is 33.

The square root of 18408444 is about 4290.5062638341. The cubic root of 18408444 is about 264.0416027182.

The spelling of 18408444 in words is "eighteen million, four hundred eight thousand, four hundred forty-four".