16253221 has 4 divisors (see below), whose sum is σ = 16274412. Its totient is φ = 16232032.

The previous prime is 16253213. The next prime is 16253233. The reversal of 16253221 is 12235261.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8328996 + 7924225 = 2886^2 + 2815^2 .

It is a cyclic number.

It is not a de Polignac number, because 16253221 - 2³ = 16253213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16253192 and 16253201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16253201) 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, 9400 + ... + 10993.

It is an arithmetic number, because the mean of its divisors is an integer number (4068603).

Almost surely, 2^16253221 is an apocalyptic number.

It is an amenable number.

16253221 is a deficient number, since it is larger than the sum of its proper divisors (21191).

16253221 is an equidigital number, since it uses as much as digits as its factorization.

16253221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21190.

The product of its digits is 720, while the sum is 22.

The square root of 16253221 is about 4031.5283702338. The cubic root of 16253221 is about 253.3065851645.

Adding to 16253221 its reverse (12235261), we get a palindrome (28488482).

The spelling of 16253221 in words is "sixteen million, two hundred fifty-three thousand, two hundred twenty-one".