123221220 has 96 divisors (see below), whose sum is σ = 354727296. Its totient is φ = 31948800.

The previous prime is 123221191. The next prime is 123221221. The reversal of 123221220 is 22122321.

It is a happy number.

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 123221220.

It is not an unprimeable number, because it can be changed into a prime (123221221) 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 31 ways as a sum of consecutive naturals, for example, 479332 + ... + 479588.

It is an arithmetic number, because the mean of its divisors is an integer number (3695076).

Almost surely, 2^123221220 is an apocalyptic number.

123221220 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 123221220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (177363648).

123221220 is an abundant number, since it is smaller than the sum of its proper divisors (231506076).

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

123221220 is a wasteful number, since it uses less digits than its factorization.

123221220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 461 (or 459 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 123221220 is about 11100.5053938999. The cubic root of 123221220 is about 497.6169535568.

Adding to 123221220 its reverse (22122321), we get a palindrome (145343541).

The spelling of 123221220 in words is "one hundred twenty-three million, two hundred twenty-one thousand, two hundred twenty".