123211220 has 48 divisors (see below), whose sum is σ = 287618688. Its totient is φ = 43954560.

The previous prime is 123211201. The next prime is 123211241. The reversal of 123211220 is 22112321.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 123211195 and 123211204.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 6377 + ... + 16943.

It is an arithmetic number, because the mean of its divisors is an integer number (5992056).

Almost surely, 2^123211220 is an apocalyptic number.

123211220 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 123211220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (143809344).

123211220 is an abundant number, since it is smaller than the sum of its proper divisors (164407468).

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

123211220 is a wasteful number, since it uses less digits than its factorization.

123211220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10640 (or 10638 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 123211220 is about 11100.0549548189. The cubic root of 123211220 is about 497.6034918490.

Adding to 123211220 its reverse (22112321), we get a palindrome (145323541).

The spelling of 123211220 in words is "one hundred twenty-three million, two hundred eleven thousand, two hundred twenty".