850817221 has 4 divisors (see below), whose sum is σ = 870603712. Its totient is φ = 831030732.

The previous prime is 850817213. The next prime is 850817249. The reversal of 850817221 is 122718058.

850817221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 122718058 = 2 ⋅61359029.

It is a cyclic number.

It is not a de Polignac number, because 850817221 - 2³ = 850817213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (850817291) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9893181 + ... + 9893266.

It is an arithmetic number, because the mean of its divisors is an integer number (217650928).

Almost surely, 2^850817221 is an apocalyptic number.

It is an amenable number.

850817221 is a deficient number, since it is larger than the sum of its proper divisors (19786491).

850817221 is a wasteful number, since it uses less digits than its factorization.

850817221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19786490.

The product of its (nonzero) digits is 8960, while the sum is 34.

The square root of 850817221 is about 29168.7713316828. The cubic root of 850817221 is about 947.5717193573.

The spelling of 850817221 in words is "eight hundred fifty million, eight hundred seventeen thousand, two hundred twenty-one".