16326721 has 2 divisors, whose sum is σ = 16326722. Its totient is φ = 16326720.

The previous prime is 16326691. The next prime is 16326763. The reversal of 16326721 is 12762361.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12852225 + 3474496 = 3585^2 + 1864^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16326721 is a prime.

It is a super-2 number, since 2×16326721² = 533123637223682, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 16326721.

It is not a weakly prime, because it can be changed into another prime (16320721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8163360 + 8163361.

It is an arithmetic number, because the mean of its divisors is an integer number (8163361).

Almost surely, 2^16326721 is an apocalyptic number.

It is an amenable number.

16326721 is a deficient number, since it is larger than the sum of its proper divisors (1).

16326721 is an equidigital number, since it uses as much as digits as its factorization.

16326721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3024, while the sum is 28.

The square root of 16326721 is about 4040.6337374229. The cubic root of 16326721 is about 253.6878437389.

The spelling of 16326721 in words is "sixteen million, three hundred twenty-six thousand, seven hundred twenty-one".