857220 has 96 divisors (see below), whose sum is σ = 2972928. Its totient is φ = 179712.

The previous prime is 857203. The next prime is 857221. The reversal of 857220 is 22758.

It is a super-2 number, since 2×857220² = 1469652256800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (857221) by changing a digit.

857220 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5382 + ... + 5538.

It is an arithmetic number, because the mean of its divisors is an integer number (30968).

2⁸⁵⁷²²⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 857220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1486464).

857220 is an abundant number, since it is smaller than the sum of its proper divisors (2115708).

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

857220 is a wasteful number, since it uses less digits than its factorization.

857220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189 (or 187 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 24.

The square root of 857220 is about 925.8617607397. The cubic root of 857220 is about 94.9942748166.

Adding to 857220 its reverse (22758), we get a palindrome (879978).

The spelling of 857220 in words is "eight hundred fifty-seven thousand, two hundred twenty".