18370221 has 8 divisors (see below), whose sum is σ = 24578400. Its totient is φ = 12204432.

The previous prime is 18370201. The next prime is 18370229. The reversal of 18370221 is 12207381.

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

It is not a de Polignac number, because 18370221 - 2¹¹ = 18368173 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 18370191 and 18370200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18370229) 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, 9571 + ... + 11328.

It is an arithmetic number, because the mean of its divisors is an integer number (3072300).

Almost surely, 2^18370221 is an apocalyptic number.

It is an amenable number.

18370221 is a deficient number, since it is larger than the sum of its proper divisors (6208179).

18370221 is a wasteful number, since it uses less digits than its factorization.

18370221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21195.

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 18370221 is about 4286.0495797412. The cubic root of 18370221 is about 263.8587254921.

The spelling of 18370221 in words is "eighteen million, three hundred seventy thousand, two hundred twenty-one".