16946221 has 2 divisors, whose sum is σ = 16946222. Its totient is φ = 16946220.

The previous prime is 16946213. The next prime is 16946249. The reversal of 16946221 is 12264961.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16933225 + 12996 = 4115^2 + 114^2 .

It is an emirp because it is prime and its reverse (12264961) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16946221 - 2³ = 16946213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16946201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8473110 + 8473111.

It is an arithmetic number, because the mean of its divisors is an integer number (8473111).

Almost surely, 2^16946221 is an apocalyptic number.

It is an amenable number.

16946221 is a deficient number, since it is larger than the sum of its proper divisors (1).

16946221 is an equidigital number, since it uses as much as digits as its factorization.

16946221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5184, while the sum is 31.

The square root of 16946221 is about 4116.5787979826. The cubic root of 16946221 is about 256.8567335259.

The spelling of 16946221 in words is "sixteen million, nine hundred forty-six thousand, two hundred twenty-one".