18312089 has 4 divisors (see below), whose sum is σ = 18331920. Its totient is φ = 18292260.

The previous prime is 18312059. The next prime is 18312101. The reversal of 18312089 is 98021381.

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, and also an emirpimes, since its reverse is a distinct semiprime: 98021381 = 43 ⋅2279567.

It is a cyclic number.

It is not a de Polignac number, because 18312089 - 2⁸ = 18311833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18312059) 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, 8459 + ... + 10400.

It is an arithmetic number, because the mean of its divisors is an integer number (4582980).

Almost surely, 2^18312089 is an apocalyptic number.

It is an amenable number.

18312089 is a deficient number, since it is larger than the sum of its proper divisors (19831).

18312089 is an equidigital number, since it uses as much as digits as its factorization.

18312089 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19830.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 18312089 is about 4279.2626701337. The cubic root of 18312089 is about 263.5801071151.

The spelling of 18312089 in words is "eighteen million, three hundred twelve thousand, eighty-nine".