18638444 has 12 divisors (see below), whose sum is σ = 35582568. Its totient is φ = 8472000.

The previous prime is 18638413. The next prime is 18638467. The reversal of 18638444 is 44483681.

It is a super-2 number, since 2×18638444² = 694783189482272, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18638398 and 18638407.

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, 211757 + ... + 211844.

It is an arithmetic number, because the mean of its divisors is an integer number (2965214).

Almost surely, 2^18638444 is an apocalyptic number.

It is an amenable number.

18638444 is a deficient number, since it is larger than the sum of its proper divisors (16944124).

18638444 is a wasteful number, since it uses less digits than its factorization.

18638444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 423616 (or 423614 counting only the distinct ones).

The product of its digits is 73728, while the sum is 38.

The square root of 18638444 is about 4317.2264244536. The cubic root of 18638444 is about 265.1367230870.

The spelling of 18638444 in words is "eighteen million, six hundred thirty-eight thousand, four hundred forty-four".