18090521 has 8 divisors (see below), whose sum is σ = 18896640. Its totient is φ = 17301168.

The previous prime is 18090517. The next prime is 18090529. The reversal of 18090521 is 12509081.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 18090521 - 2² = 18090517 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18090529) 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, 1961 + ... + 6326.

It is an arithmetic number, because the mean of its divisors is an integer number (2362080).

Almost surely, 2^18090521 is an apocalyptic number.

It is an amenable number.

18090521 is a deficient number, since it is larger than the sum of its proper divisors (806119).

18090521 is an equidigital number, since it uses as much as digits as its factorization.

18090521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8383.

The product of its (nonzero) digits is 720, while the sum is 26.

The square root of 18090521 is about 4253.2953106973. The cubic root of 18090521 is about 262.5127237975.

The spelling of 18090521 in words is "eighteen million, ninety thousand, five hundred twenty-one".