18638436 has 48 divisors (see below), whose sum is σ = 45638208. Its totient is φ = 5913600.

The previous prime is 18638413. The next prime is 18638467. The reversal of 18638436 is 63483681.

It is a junction number, because it is equal to n+sod(n) for n = 18638394 and 18638403.

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 15 ways as a sum of consecutive naturals, for example, 20716 + ... + 21596.

It is an arithmetic number, because the mean of its divisors is an integer number (950796).

Almost surely, 2^18638436 is an apocalyptic number.

It is an amenable number.

18638436 is an abundant number, since it is smaller than the sum of its proper divisors (26999772).

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

18638436 is a wasteful number, since it uses less digits than its factorization.

18638436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 972 (or 970 counting only the distinct ones).

The product of its digits is 82944, while the sum is 39.

The square root of 18638436 is about 4317.2254979327. The cubic root of 18638436 is about 265.1366851529.

The spelling of 18638436 in words is "eighteen million, six hundred thirty-eight thousand, four hundred thirty-six".