18986478 has 32 divisors (see below), whose sum is σ = 44411136. Its totient is φ = 5298048.

The previous prime is 18986447. The next prime is 18986483. The reversal of 18986478 is 87468981.

It is a self number, because there is not a number n which added to its sum of digits gives 18986478.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3451 + ... + 7062.

It is an arithmetic number, because the mean of its divisors is an integer number (1387848).

Almost surely, 2^18986478 is an apocalyptic number.

18986478 is an abundant number, since it is smaller than the sum of its proper divisors (25424658).

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

18986478 is a wasteful number, since it uses less digits than its factorization.

18986478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10568.

The product of its digits is 774144, while the sum is 51.

The square root of 18986478 is about 4357.3475876960. The cubic root of 18986478 is about 266.7768478719.

The spelling of 18986478 in words is "eighteen million, nine hundred eighty-six thousand, four hundred seventy-eight".