1211012220 has 192 divisors, whose sum is σ = 3844495872. Its totient is φ = 282240000.

The previous prime is 1211012213. The next prime is 1211012233. The reversal of 1211012220 is 222101121.

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 = 1211012196 and 1211012205.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2466175 + ... + 2466665.

It is an arithmetic number, because the mean of its divisors is an integer number (20023416).

Almost surely, 2^1211012220 is an apocalyptic number.

1211012220 is a gapful number since it is divisible by the number (10) 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 1211012220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1922247936).

1211012220 is an abundant number, since it is smaller than the sum of its proper divisors (2633483652).

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

1211012220 is a wasteful number, since it uses less digits than its factorization.

1211012220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 652 (or 650 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 1211012220 is about 34799.6008597800. The cubic root of 1211012220 is about 1065.8992955168.

Adding to 1211012220 its reverse (222101121), we get a palindrome (1433113341).

It can be divided in two parts, 121101 and 2220, that added together give a palindrome (123321).

The spelling of 1211012220 in words is "one billion, two hundred eleven million, twelve thousand, two hundred twenty".