18478438 has 16 divisors (see below), whose sum is σ = 30509136. Its totient is φ = 8323840.

The previous prime is 18478409. The next prime is 18478441. The reversal of 18478438 is 83487481.

It is a junction number, because it is equal to n+sod(n) for n = 18478394 and 18478403.

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, 1231 + ... + 6202.

It is an arithmetic number, because the mean of its divisors is an integer number (1906821).

Almost surely, 2^18478438 is an apocalyptic number.

18478438 is a deficient number, since it is larger than the sum of its proper divisors (12030698).

18478438 is a wasteful number, since it uses less digits than its factorization.

18478438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7559.

The product of its digits is 172032, while the sum is 43.

The square root of 18478438 is about 4298.6553711597. The cubic root of 18478438 is about 264.3758325529.

The spelling of 18478438 in words is "eighteen million, four hundred seventy-eight thousand, four hundred thirty-eight".