18213808 has 10 divisors (see below), whose sum is σ = 35289284. Its totient is φ = 9106896.

The previous prime is 18213803. The next prime is 18213823. The reversal of 18213808 is 80831281.

It is a self number, because there is not a number n which added to its sum of digits gives 18213808.

It is not an unprimeable number, because it can be changed into a prime (18213803) 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 as a sum of consecutive naturals, namely, 569166 + ... + 569197.

Almost surely, 2^18213808 is an apocalyptic number.

It is an amenable number.

18213808 is a deficient number, since it is larger than the sum of its proper divisors (17075476).

18213808 is a wasteful number, since it uses less digits than its factorization.

18213808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1138371 (or 1138365 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 31.

The square root of 18213808 is about 4267.7638172701. The cubic root of 18213808 is about 263.1077160972.

The spelling of 18213808 in words is "eighteen million, two hundred thirteen thousand, eight hundred eight".