16427221 has 4 divisors (see below), whose sum is σ = 17141472. Its totient is φ = 15712972.

The previous prime is 16427209. The next prime is 16427227. The reversal of 16427221 is 12272461.

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 a cyclic number.

It is not a de Polignac number, because 16427221 - 2⁷ = 16427093 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 (16427227) 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, 357091 + ... + 357136.

It is an arithmetic number, because the mean of its divisors is an integer number (4285368).

Almost surely, 2^16427221 is an apocalyptic number.

It is an amenable number.

16427221 is a deficient number, since it is larger than the sum of its proper divisors (714251).

16427221 is an equidigital number, since it uses as much as digits as its factorization.

16427221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 714250.

The product of its digits is 1344, while the sum is 25.

The square root of 16427221 is about 4053.0508262295. The cubic root of 16427221 is about 254.2073090014.

Adding to 16427221 its reverse (12272461), we get a palindrome (28699682).

The spelling of 16427221 in words is "sixteen million, four hundred twenty-seven thousand, two hundred twenty-one".