18089921 has 8 divisors (see below), whose sum is σ = 19302624. Its totient is φ = 16893760.

The previous prime is 18089917. The next prime is 18089923. The reversal of 18089921 is 12998081.

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

It is not a de Polignac number, because 18089921 - 2² = 18089917 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18089923) 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, 1835 + ... + 6288.

It is an arithmetic number, because the mean of its divisors is an integer number (2412828).

Almost surely, 2^18089921 is an apocalyptic number.

It is an amenable number.

18089921 is a deficient number, since it is larger than the sum of its proper divisors (1212703).

18089921 is a wasteful number, since it uses less digits than its factorization.

18089921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8271.

The product of its (nonzero) digits is 10368, while the sum is 38.

The square root of 18089921 is about 4253.2247765666. The cubic root of 18089921 is about 262.5098215524.

The spelling of 18089921 in words is "eighteen million, eighty-nine thousand, nine hundred twenty-one".