850216021 has 4 divisors (see below), whose sum is σ = 859769100. Its totient is φ = 840662944.

The previous prime is 850215979. The next prime is 850216039. The reversal of 850216021 is 120612058.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 143400625 + 706815396 = 11975^2 + 26586^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-850216021 is a prime.

It is a super-4 number, since 4×850216021⁴ (a number of 37 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (850216421) 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, 4776406 + ... + 4776583.

It is an arithmetic number, because the mean of its divisors is an integer number (214942275).

Almost surely, 2^850216021 is an apocalyptic number.

It is an amenable number.

850216021 is a deficient number, since it is larger than the sum of its proper divisors (9553079).

850216021 is an equidigital number, since it uses as much as digits as its factorization.

850216021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9553078.

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 850216021 is about 29158.4639684603. The cubic root of 850216021 is about 947.3484773817.

Adding to 850216021 its reverse (120612058), we get a palindrome (970828079).

The spelling of 850216021 in words is "eight hundred fifty million, two hundred sixteen thousand, twenty-one".