211021220 has 48 divisors (see below), whose sum is σ = 467812800. Its totient is φ = 79735680.

The previous prime is 211021199. The next prime is 211021231. The reversal of 211021220 is 22120112.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 192875 + ... + 193965.

It is an arithmetic number, because the mean of its divisors is an integer number (9746100).

Almost surely, 2^211021220 is an apocalyptic number.

211021220 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 211021220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (233906400).

211021220 is an abundant number, since it is smaller than the sum of its proper divisors (256791580).

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

211021220 is a wasteful number, since it uses less digits than its factorization.

211021220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1628 (or 1626 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 211021220 is about 14526.5694504931. The cubic root of 211021220 is about 595.3541379772.

Adding to 211021220 its reverse (22120112), we get a palindrome (233141332).

It can be divided in two parts, 21102 and 1220, that added together give a palindrome (22322).

The spelling of 211021220 in words is "two hundred eleven million, twenty-one thousand, two hundred twenty".