18638406 has 12 divisors (see below), whose sum is σ = 40383252. Its totient is φ = 6212796.

The previous prime is 18638381. The next prime is 18638413. The reversal of 18638406 is 60483681.

It is a happy number.

18638406 is a `hidden beast` number, since 18 + 638 + 4 + 0 + 6 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 517716 + ... + 517751.

It is an arithmetic number, because the mean of its divisors is an integer number (3365271).

Almost surely, 2^18638406 is an apocalyptic number.

18638406 is an abundant number, since it is smaller than the sum of its proper divisors (21744846).

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

18638406 is a wasteful number, since it uses less digits than its factorization.

18638406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1035475 (or 1035472 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 18638406 is about 4317.2220234776. Note that the first 3 decimals coincide. The cubic root of 18638406 is about 265.1365429002.

It can be divided in two parts, 18638 and 406, that added together give a square (19044 = 138²).

The spelling of 18638406 in words is "eighteen million, six hundred thirty-eight thousand, four hundred six".