18109887 has 8 divisors (see below), whose sum is σ = 24237360. Its totient is φ = 12027840.

The previous prime is 18109849. The next prime is 18109937. The reversal of 18109887 is 78890181.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18109887 - 2⁷ = 18109759 is a prime.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18109807) 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, 10414 + ... + 12027.

It is an arithmetic number, because the mean of its divisors is an integer number (3029670).

Almost surely, 2^18109887 is an apocalyptic number.

18109887 is a deficient number, since it is larger than the sum of its proper divisors (6127473).

18109887 is a wasteful number, since it uses less digits than its factorization.

18109887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22713.

The product of its (nonzero) digits is 32256, while the sum is 42.

The square root of 18109887 is about 4255.5712894980. The cubic root of 18109887 is about 262.6063641520.

The spelling of 18109887 in words is "eighteen million, one hundred nine thousand, eight hundred eighty-seven".