1222220100 has 144 divisors (see below), whose sum is σ = 3760259328. Its totient is φ = 305448960.

The previous prime is 1222220081. The next prime is 1222220107. The reversal of 1222220100 is 10222221.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (1222220107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1871374 + ... + 1872026.

It is an arithmetic number, because the mean of its divisors is an integer number (26112912).

Almost surely, 2^1222220100 is an apocalyptic number.

1222220100 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 1222220100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1880129664).

1222220100 is an abundant number, since it is smaller than the sum of its proper divisors (2538039228).

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

1222220100 is a wasteful number, since it uses less digits than its factorization.

1222220100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1054 (or 1047 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 1222220100 is about 34960.2645870995. The cubic root of 1222220100 is about 1069.1774911709.

Adding to 1222220100 its reverse (10222221), we get a palindrome (1232442321).

It can be divided in two parts, 122 and 2220100, that added together give a palindrome (2220222).

The spelling of 1222220100 in words is "one billion, two hundred twenty-two million, two hundred twenty thousand, one hundred".