1211330220 has 48 divisors (see below), whose sum is σ = 3432602880. Its totient is φ = 319128256.

The previous prime is 1211330171. The next prime is 1211330221. The reversal of 1211330220 is 220331121.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1211330220.

It is not an unprimeable number, because it can be changed into a prime (1211330221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 116640 + ... + 126599.

It is an arithmetic number, because the mean of its divisors is an integer number (71512560).

Almost surely, 2^1211330220 is an apocalyptic number.

1211330220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211330220 is an abundant number, since it is smaller than the sum of its proper divisors (2221272660).

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

1211330220 is a wasteful number, since it uses less digits than its factorization.

1211330220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243334 (or 243332 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 1211330220 is about 34804.1695777963. The cubic root of 1211330220 is about 1065.9925856053.

Adding to 1211330220 its reverse (220331121), we get a palindrome (1431661341).

Subtracting from 1211330220 its reverse (220331121), we obtain a palindrome (990999099).

The spelling of 1211330220 in words is "one billion, two hundred eleven million, three hundred thirty thousand, two hundred twenty".