18978066 has 12 divisors (see below), whose sum is σ = 41119182. Its totient is φ = 6326016.

The previous prime is 18978053. The next prime is 18978067. The reversal of 18978066 is 66087981.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 15093225 + 3884841 = 3885^2 + 1971^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18978067) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 527151 + ... + 527186.

Almost surely, 2^18978066 is an apocalyptic number.

18978066 is an abundant number, since it is smaller than the sum of its proper divisors (22141116).

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

18978066 is a wasteful number, since it uses less digits than its factorization.

18978066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1054345 (or 1054342 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 18978066 is about 4356.3822146364. The cubic root of 18978066 is about 266.7374433661.

The spelling of 18978066 in words is "eighteen million, nine hundred seventy-eight thousand, sixty-six".