16247221 has 4 divisors (see below), whose sum is σ = 16807500. Its totient is φ = 15686944.

The previous prime is 16247207. The next prime is 16247233. The reversal of 16247221 is 12274261.

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 3186225 + 13060996 = 1785^2 + 3614^2 .

It is a cyclic number.

It is not a de Polignac number, because 16247221 - 2¹⁵ = 16214453 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 (16247251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 280096 + ... + 280153.

It is an arithmetic number, because the mean of its divisors is an integer number (4201875).

Almost surely, 2^16247221 is an apocalyptic number.

It is an amenable number.

16247221 is a deficient number, since it is larger than the sum of its proper divisors (560279).

16247221 is an equidigital number, since it uses as much as digits as its factorization.

16247221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 560278.

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

The square root of 16247221 is about 4030.7841668837. The cubic root of 16247221 is about 253.2754113115.

The spelling of 16247221 in words is "sixteen million, two hundred forty-seven thousand, two hundred twenty-one".