16643213 has 2 divisors, whose sum is σ = 16643214. Its totient is φ = 16643212.

The previous prime is 16643201. The next prime is 16643227. The reversal of 16643213 is 31234661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15382084 + 1261129 = 3922^2 + 1123^2 .

It is a cyclic number.

It is not a de Polignac number, because 16643213 - 2¹⁴ = 16626829 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16643233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8321606 + 8321607.

It is an arithmetic number, because the mean of its divisors is an integer number (8321607).

Almost surely, 2^16643213 is an apocalyptic number.

It is an amenable number.

16643213 is a deficient number, since it is larger than the sum of its proper divisors (1).

16643213 is an equidigital number, since it uses as much as digits as its factorization.

16643213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592, while the sum is 26.

The square root of 16643213 is about 4079.6094175791. The cubic root of 16643213 is about 255.3166027770.

Adding to 16643213 its reverse (31234661), we get a palindrome (47877874).

The spelling of 16643213 in words is "sixteen million, six hundred forty-three thousand, two hundred thirteen".