18978998 has 8 divisors (see below), whose sum is σ = 28509240. Its totient is φ = 9475920.

The previous prime is 18978989. The next prime is 18979003. The reversal of 18978998 is 89987981.

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

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 3 ways as a sum of consecutive naturals, for example, 4943 + ... + 7898.

It is an arithmetic number, because the mean of its divisors is an integer number (3563655).

Almost surely, 2^18978998 is an apocalyptic number.

18978998 is a deficient number, since it is larger than the sum of its proper divisors (9530242).

18978998 is a wasteful number, since it uses less digits than its factorization.

18978998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13582.

The product of its digits is 2612736, while the sum is 59.

The square root of 18978998 is about 4356.4891828168. The cubic root of 18978998 is about 266.7418097265.

The spelling of 18978998 in words is "eighteen million, nine hundred seventy-eight thousand, nine hundred ninety-eight".