212820 has 24 divisors (see below), whose sum is σ = 596064.
Its totient is φ = 56736.
The previous prime is 212801. The next prime is 212827. The reversal of 212820 is 28212.
212820 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.
It is a Harshad number since it is a multiple of its sum of digits (15).
It is an Ulam number.
It is a self number, because there is not a number n which added to its sum of digits gives 212820.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (212827) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (11) of ones.
It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1714 + ... + 1833.
It is an arithmetic number, because the mean of its divisors is an integer number (24836).
2212820 is an apocalyptic number.
212820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.
It is an amenable number.
212820 is an abundant number, since it is smaller than the sum of its proper divisors (383244).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
212820 is a wasteful number, since it uses less digits than its factorization.
212820 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 3559 (or 3557 counting only the distinct ones).
The product of its (nonzero) digits is 64, while the sum is 15.
The square root of 212820 is about 461.3241810267.
The cubic root of 212820 is about 59.7040986611.
The spelling of 212820 in words is "two hundred twelve thousand, eight hundred twenty".