18894978 has 16 divisors (see below), whose sum is σ = 41988960. Its totient is φ = 6298308.

The previous prime is 18894971. The next prime is 18894989. The reversal of 18894978 is 87949881.

It is a Harshad number since it is a multiple of its sum of digits (54), and also a Moran number because the ratio is a prime number: 349907 = 18894978 / (1 + 8 + 8 + 9 + 4 + 9 + 7 + 8).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18894971) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 174900 + ... + 175007.

It is an arithmetic number, because the mean of its divisors is an integer number (2624310).

Almost surely, 2^18894978 is an apocalyptic number.

18894978 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

18894978 is an abundant number, since it is smaller than the sum of its proper divisors (23093982).

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

18894978 is a wasteful number, since it uses less digits than its factorization.

18894978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 349918 (or 349912 counting only the distinct ones).

The product of its digits is 1161216, while the sum is 54.

The square root of 18894978 is about 4346.8354006104. The cubic root of 18894978 is about 266.3476055551.

The spelling of 18894978 in words is "eighteen million, eight hundred ninety-four thousand, nine hundred seventy-eight".