1222211220 has 24 divisors (see below), whose sum is σ = 3422191584. Its totient is φ = 325922976.

The previous prime is 1222211213. The next prime is 1222211227. The reversal of 1222211220 is 221122221.

It is an interprime number because it is at equal distance from previous prime (1222211213) and next prime (1222211227).

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 1222211220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1222211227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10185034 + ... + 10185153.

It is an arithmetic number, because the mean of its divisors is an integer number (142591316).

Almost surely, 2^1222211220 is an apocalyptic number.

1222211220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1222211220 is an abundant number, since it is smaller than the sum of its proper divisors (2199980364).

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

1222211220 is a wasteful number, since it uses less digits than its factorization.

1222211220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20370199 (or 20370197 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 1222211220 is about 34960.1375855416. The cubic root of 1222211220 is about 1069.1749018067.

Adding to 1222211220 its reverse (221122221), we get a palindrome (1443333441).

The spelling of 1222211220 in words is "one billion, two hundred twenty-two million, two hundred eleven thousand, two hundred twenty".