18306978 has 16 divisors (see below), whose sum is σ = 37056096. Its totient is φ = 6028640.

The previous prime is 18306973. The next prime is 18306979. The reversal of 18306978 is 87960381.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18306973) 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 in 7 ways as a sum of consecutive naturals, for example, 17883 + ... + 18878.

It is an arithmetic number, because the mean of its divisors is an integer number (2316006).

Almost surely, 2^18306978 is an apocalyptic number.

18306978 is an abundant number, since it is smaller than the sum of its proper divisors (18749118).

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

18306978 is a wasteful number, since it uses less digits than its factorization.

18306978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36849.

The product of its (nonzero) digits is 72576, while the sum is 42.

The square root of 18306978 is about 4278.6654461409. The cubic root of 18306978 is about 263.5555826370. Note that the first 4 decimals are identical.

The spelling of 18306978 in words is "eighteen million, three hundred six thousand, nine hundred seventy-eight".