18997808 has 10 divisors (see below), whose sum is σ = 36808284. Its totient is φ = 9498896.

The previous prime is 18997799. The next prime is 18997817. The reversal of 18997808 is 80879981.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18997799) and next prime (18997817).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 593666 + ... + 593697.

Almost surely, 2^18997808 is an apocalyptic number.

It is an amenable number.

18997808 is a deficient number, since it is larger than the sum of its proper divisors (17810476).

18997808 is a wasteful number, since it uses less digits than its factorization.

18997808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1187371 (or 1187365 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 50.

The square root of 18997808 is about 4358.6474966439. The cubic root of 18997808 is about 266.8299028347.

The spelling of 18997808 in words is "eighteen million, nine hundred ninety-seven thousand, eight hundred eight".