849684221 has 2 divisors, whose sum is σ = 849684222. Its totient is φ = 849684220.

The previous prime is 849684217. The next prime is 849684223. The reversal of 849684221 is 122486948.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 847624996 + 2059225 = 29114^2 + 1435^2 .

It is a cyclic number.

It is not a de Polignac number, because 849684221 - 2² = 849684217 is a prime.

Together with 849684223, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (849684223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 424842110 + 424842111.

It is an arithmetic number, because the mean of its divisors is an integer number (424842111).

Almost surely, 2^849684221 is an apocalyptic number.

It is an amenable number.

849684221 is a deficient number, since it is larger than the sum of its proper divisors (1).

849684221 is an equidigital number, since it uses as much as digits as its factorization.

849684221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 221184, while the sum is 44.

The square root of 849684221 is about 29149.3434059843. The cubic root of 849684221 is about 947.1509177872.

The spelling of 849684221 in words is "eight hundred forty-nine million, six hundred eighty-four thousand, two hundred twenty-one".