18408887 has 4 divisors (see below), whose sum is σ = 21038736. Its totient is φ = 15779040.

The previous prime is 18408883. The next prime is 18408917. The reversal of 18408887 is 78880481.

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

It is a cyclic number.

It is not a de Polignac number, because 18408887 - 2² = 18408883 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18408883) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1314914 + ... + 1314927.

It is an arithmetic number, because the mean of its divisors is an integer number (5259684).

Almost surely, 2^18408887 is an apocalyptic number.

18408887 is a deficient number, since it is larger than the sum of its proper divisors (2629849).

18408887 is an equidigital number, since it uses as much as digits as its factorization.

18408887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2629848.

The product of its (nonzero) digits is 114688, while the sum is 44.

The square root of 18408887 is about 4290.5578891328. The cubic root of 18408887 is about 264.0437207587.

The spelling of 18408887 in words is "eighteen million, four hundred eight thousand, eight hundred eighty-seven".