1211122220 has 72 divisors (see below), whose sum is σ = 3227590800. Its totient is φ = 377489280.

The previous prime is 1211122207. The next prime is 1211122261. The reversal of 1211122220 is 222211121.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a junction number, because it is equal to n+sod(n) for n = 1211122195 and 1211122204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 45395 + ... + 66954.

It is an arithmetic number, because the mean of its divisors is an integer number (44827650).

Almost surely, 2^1211122220 is an apocalyptic number.

1211122220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211122220 is an abundant number, since it is smaller than the sum of its proper divisors (2016468580).

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

1211122220 is a wasteful number, since it uses less digits than its factorization.

1211122220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112383 (or 112374 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 1211122220 is about 34801.1813017892. The cubic root of 1211122220 is about 1065.9315675205.

Adding to 1211122220 its reverse (222211121), we get a palindrome (1433333341).

The spelling of 1211122220 in words is "one billion, two hundred eleven million, one hundred twenty-two thousand, two hundred twenty".