212831220 has 96 divisors (see below), whose sum is σ = 687456000. Its totient is φ = 48190464.

The previous prime is 212831207. The next prime is 212831221. The reversal of 212831220 is 22138212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212831221) 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 in 31 ways as a sum of consecutive naturals, for example, 43456 + ... + 48104.

It is an arithmetic number, because the mean of its divisors is an integer number (7161000).

Almost surely, 2^212831220 is an apocalyptic number.

212831220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 212831220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (343728000).

212831220 is an abundant number, since it is smaller than the sum of its proper divisors (474624780).

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

212831220 is a wasteful number, since it uses less digits than its factorization.

212831220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4777 (or 4775 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 212831220 is about 14588.7360658832. The cubic root of 212831220 is about 597.0514785482.

Adding to 212831220 its reverse (22138212), we get a palindrome (234969432).

The spelling of 212831220 in words is "two hundred twelve million, eight hundred thirty-one thousand, two hundred twenty".