1211000220 has 84 divisors (see below), whose sum is σ = 3812952360. Its totient is φ = 322929504.

The previous prime is 1211000159. The next prime is 1211000221. The reversal of 1211000220 is 220001121.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211000221) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 26950 + ... + 56109.

It is an arithmetic number, because the mean of its divisors is an integer number (45392290).

Almost surely, 2^1211000220 is an apocalyptic number.

1211000220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211000220 is an abundant number, since it is smaller than the sum of its proper divisors (2601952140).

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

1211000220 is an equidigital number, since it uses as much as digits as its factorization.

1211000220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83086 (or 83069 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 1211000220 is about 34799.4284435822. The cubic root of 1211000220 is about 1065.8957748163.

Adding to 1211000220 its reverse (220001121), we get a palindrome (1431001341).

Subtracting from 1211000220 its reverse (220001121), we obtain a palindrome (990999099).

The spelling of 1211000220 in words is "one billion, two hundred eleven million, two hundred twenty", and thus it is an aban number.