16970221 has 2 divisors, whose sum is σ = 16970222. Its totient is φ = 16970220.

The previous prime is 16970209. The next prime is 16970231. The reversal of 16970221 is 12207961.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12152196 + 4818025 = 3486^2 + 2195^2 .

It is a cyclic number.

It is not a de Polignac number, because 16970221 - 2⁵ = 16970189 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16970221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16970231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8485110 + 8485111.

It is an arithmetic number, because the mean of its divisors is an integer number (8485111).

Almost surely, 2^16970221 is an apocalyptic number.

It is an amenable number.

16970221 is a deficient number, since it is larger than the sum of its proper divisors (1).

16970221 is an equidigital number, since it uses as much as digits as its factorization.

16970221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1512, while the sum is 28.

The square root of 16970221 is about 4119.4928085870. The cubic root of 16970221 is about 256.9779336785.

The spelling of 16970221 in words is "sixteen million, nine hundred seventy thousand, two hundred twenty-one".