18290221 has 8 divisors (see below), whose sum is σ = 19154304. Its totient is φ = 17431920.

The previous prime is 18290219. The next prime is 18290243. The reversal of 18290221 is 12209281.

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 18290221 - 2¹ = 18290219 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 (18290291) 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, 5875 + ... + 8431.

It is an arithmetic number, because the mean of its divisors is an integer number (2394288).

Almost surely, 2^18290221 is an apocalyptic number.

It is an amenable number.

18290221 is a deficient number, since it is larger than the sum of its proper divisors (864083).

18290221 is a wasteful number, since it uses less digits than its factorization.

18290221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2891.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 18290221 is about 4276.7067937842. The cubic root of 18290221 is about 263.4751442912.

The spelling of 18290221 in words is "eighteen million, two hundred ninety thousand, two hundred twenty-one".