18478478 has 4 divisors (see below), whose sum is σ = 27717720. Its totient is φ = 9239238.

The previous prime is 18478477. The next prime is 18478483. The reversal of 18478478 is 87487481.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18478477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4619618 + ... + 4619621.

It is an arithmetic number, because the mean of its divisors is an integer number (6929430).

Almost surely, 2^18478478 is an apocalyptic number.

18478478 is a deficient number, since it is larger than the sum of its proper divisors (9239242).

18478478 is an equidigital number, since it uses as much as digits as its factorization.

18478478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9239241.

The product of its digits is 401408, while the sum is 47.

The square root of 18478478 is about 4298.6600237749. The cubic root of 18478478 is about 264.3760233163.

The spelling of 18478478 in words is "eighteen million, four hundred seventy-eight thousand, four hundred seventy-eight".