18087289 has 4 divisors (see below), whose sum is σ = 19731600. Its totient is φ = 16442980.

The previous prime is 18087263. The next prime is 18087313. The reversal of 18087289 is 98278081.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18087289 - 2¹⁵ = 18054521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18087389) 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, 822139 + ... + 822160.

It is an arithmetic number, because the mean of its divisors is an integer number (4932900).

Almost surely, 2^18087289 is an apocalyptic number.

It is an amenable number.

18087289 is a deficient number, since it is larger than the sum of its proper divisors (1644311).

18087289 is a wasteful number, since it uses less digits than its factorization.

18087289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1644310.

The product of its (nonzero) digits is 64512, while the sum is 43.

The square root of 18087289 is about 4252.9153530255. The cubic root of 18087289 is about 262.4970896125.

The spelling of 18087289 in words is "eighteen million, eighty-seven thousand, two hundred eighty-nine".