1212011220 has 192 divisors, whose sum is σ = 4157669376. Its totient is φ = 257748480.

The previous prime is 1212011179. The next prime is 1212011233. The reversal of 1212011220 is 221102121.

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 = 1212011196 and 1212011205.

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, 355725 + ... + 359115.

It is an arithmetic number, because the mean of its divisors is an integer number (21654528).

Almost surely, 2^1212011220 is an apocalyptic number.

1212011220 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 1212011220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2078834688).

1212011220 is an abundant number, since it is smaller than the sum of its proper divisors (2945658156).

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

1212011220 is a wasteful number, since it uses less digits than its factorization.

1212011220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3470 (or 3468 counting only the distinct ones).

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

The square root of 1212011220 is about 34813.9515137251. The cubic root of 1212011220 is about 1066.1923123029.

Adding to 1212011220 its reverse (221102121), we get a palindrome (1433113341).

Subtracting from 1212011220 its reverse (221102121), we obtain a palindrome (990909099).

The spelling of 1212011220 in words is "one billion, two hundred twelve million, eleven thousand, two hundred twenty".