18160221 has 4 divisors (see below), whose sum is σ = 24213632. Its totient is φ = 12106812.

The previous prime is 18160213. The next prime is 18160277. The reversal of 18160221 is 12206181.

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.

It is not a de Polignac number, because 18160221 - 2³ = 18160213 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 (18160421) 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, 3026701 + ... + 3026706.

It is an arithmetic number, because the mean of its divisors is an integer number (6053408).

Almost surely, 2^18160221 is an apocalyptic number.

It is an amenable number.

18160221 is a deficient number, since it is larger than the sum of its proper divisors (6053411).

18160221 is an equidigital number, since it uses as much as digits as its factorization.

18160221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6053410.

The product of its (nonzero) digits is 192, while the sum is 21.

The square root of 18160221 is about 4261.4810805634. The cubic root of 18160221 is about 262.8494321457.

It can be divided in two parts, 18160 and 221, that added together give a palindrome (18381).

The spelling of 18160221 in words is "eighteen million, one hundred sixty thousand, two hundred twenty-one".