18300221 has 4 divisors (see below), whose sum is σ = 18319200. Its totient is φ = 18281244.

The previous prime is 18300197. The next prime is 18300223. The reversal of 18300221 is 12200381.

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: 12200381 = 1279 ⋅9539.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18300221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18300221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18300223) 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, 7961 + ... + 9998.

It is an arithmetic number, because the mean of its divisors is an integer number (4579800).

Almost surely, 2^18300221 is an apocalyptic number.

It is an amenable number.

18300221 is a deficient number, since it is larger than the sum of its proper divisors (18979).

18300221 is a wasteful number, since it uses less digits than its factorization.

18300221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18978.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 18300221 is about 4277.8757578967. The cubic root of 18300221 is about 263.5231530316.

The spelling of 18300221 in words is "eighteen million, three hundred thousand, two hundred twenty-one".