856011220 has 24 divisors (see below), whose sum is σ = 1803771144. Its totient is φ = 341233536.

The previous prime is 856011203. The next prime is 856011283. The reversal of 856011220 is 22110658.

It can be written as a sum of positive squares in 4 ways, for example, as 99321156 + 756690064 = 9966^2 + 27508^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67179 + ... + 78898.

It is an arithmetic number, because the mean of its divisors is an integer number (75157131).

Almost surely, 2^856011220 is an apocalyptic number.

It is an amenable number.

856011220 is an abundant number, since it is smaller than the sum of its proper divisors (947759924).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

856011220 is a wasteful number, since it uses less digits than its factorization.

856011220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146379 (or 146377 counting only the distinct ones).

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

The square root of 856011220 is about 29257.6694218798. The cubic root of 856011220 is about 949.4960281674.

Adding to 856011220 its reverse (22110658), we get a palindrome (878121878).

The spelling of 856011220 in words is "eight hundred fifty-six million, eleven thousand, two hundred twenty".