16299221 has 4 divisors (see below), whose sum is σ = 16522572. Its totient is φ = 16075872.

The previous prime is 16299161. The next prime is 16299251. The reversal of 16299221 is 12299261.

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 10491121 + 5808100 = 3239^2 + 2410^2 .

It is a cyclic number.

It is not a de Polignac number, because 16299221 - 2¹⁴ = 16282837 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 (16299251) 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, 111566 + ... + 111711.

It is an arithmetic number, because the mean of its divisors is an integer number (4130643).

Almost surely, 2^16299221 is an apocalyptic number.

It is an amenable number.

16299221 is a deficient number, since it is larger than the sum of its proper divisors (223351).

16299221 is an equidigital number, since it uses as much as digits as its factorization.

16299221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223350.

The product of its digits is 3888, while the sum is 32.

The square root of 16299221 is about 4037.2293717350. The cubic root of 16299221 is about 253.5453302014.

The spelling of 16299221 in words is "sixteen million, two hundred ninety-nine thousand, two hundred twenty-one".