212021220 has 96 divisors (see below), whose sum is σ = 610727040. Its totient is φ = 54937600.

The previous prime is 212021213. The next prime is 212021237. The reversal of 212021220 is 22120212.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 212021196 and 212021205.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 357244 + ... + 357836.

It is an arithmetic number, because the mean of its divisors is an integer number (6361740).

Almost surely, 2^212021220 is an apocalyptic number.

212021220 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 212021220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (305363520).

212021220 is an abundant number, since it is smaller than the sum of its proper divisors (398705820).

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

212021220 is a wasteful number, since it uses less digits than its factorization.

212021220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 765 (or 763 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 212021220 is about 14560.9484581191. The cubic root of 212021220 is about 596.2930896346.

Adding to 212021220 its reverse (22120212), we get a palindrome (234141432).

It can be divided in two parts, 21202 and 1220, that added together give a palindrome (22422).

The spelling of 212021220 in words is "two hundred twelve million, twenty-one thousand, two hundred twenty".