18938478 has 48 divisors (see below), whose sum is σ = 43217280. Its totient is φ = 5514912.

The previous prime is 18938477. The next prime is 18938501. The reversal of 18938478 is 87483981.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18938471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18775 + ... + 19757.

It is an arithmetic number, because the mean of its divisors is an integer number (900360).

Almost surely, 2^18938478 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18938478, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21608640).

18938478 is an abundant number, since it is smaller than the sum of its proper divisors (24278802).

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

18938478 is a wasteful number, since it uses less digits than its factorization.

18938478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1033 (or 1020 counting only the distinct ones).

The product of its digits is 387072, while the sum is 48.

The square root of 18938478 is about 4351.8361641955. The cubic root of 18938478 is about 266.5518439689.

The spelling of 18938478 in words is "eighteen million, nine hundred thirty-eight thousand, four hundred seventy-eight".