18109678 has 4 divisors (see below), whose sum is σ = 27164520. Its totient is φ = 9054838.

The previous prime is 18109667. The next prime is 18109681. The reversal of 18109678 is 87690181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87690181 = 557 ⋅157433.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an alternating number because its digits alternate between odd and even.

It is a self number, because there is not a number n which added to its sum of digits gives 18109678.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4527418 + ... + 4527421.

It is an arithmetic number, because the mean of its divisors is an integer number (6791130).

Almost surely, 2^18109678 is an apocalyptic number.

18109678 is a deficient number, since it is larger than the sum of its proper divisors (9054842).

18109678 is an equidigital number, since it uses as much as digits as its factorization.

18109678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9054841.

The product of its (nonzero) digits is 24192, while the sum is 40.

The square root of 18109678 is about 4255.5467333822. The cubic root of 18109678 is about 262.6053539314.

The spelling of 18109678 in words is "eighteen million, one hundred nine thousand, six hundred seventy-eight".