18978618 has 8 divisors (see below), whose sum is σ = 37957248. Its totient is φ = 6326204.

The previous prime is 18978601. The next prime is 18978637. The reversal of 18978618 is 81687981.

It is a sphenic number, since it is the product of 3 distinct primes.

18978618 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1581546 + ... + 1581557.

It is an arithmetic number, because the mean of its divisors is an integer number (4744656).

Almost surely, 2^18978618 is an apocalyptic number.

18978618 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

18978618 is a wasteful number, since it uses less digits than its factorization.

18978618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3163108.

The product of its digits is 193536, while the sum is 48.

The square root of 18978618 is about 4356.4455694981. The cubic root of 18978618 is about 266.7400294680.

The spelling of 18978618 in words is "eighteen million, nine hundred seventy-eight thousand, six hundred eighteen".