123121220 has 24 divisors (see below), whose sum is σ = 258816600. Its totient is φ = 49198592.

The previous prime is 123121217. The next prime is 123121249. The reversal of 123121220 is 22121321.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 44302336 + 78818884 = 6656^2 + 8878^2 .

It is a junction number, because it is equal to n+sod(n) for n = 123121195 and 123121204.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22076 + ... + 27084.

It is an arithmetic number, because the mean of its divisors is an integer number (10784025).

Almost surely, 2^123121220 is an apocalyptic number.

123121220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

123121220 is an abundant number, since it is smaller than the sum of its proper divisors (135695380).

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

123121220 is a wasteful number, since it uses less digits than its factorization.

123121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6247 (or 6245 counting only the distinct ones).

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

The square root of 123121220 is about 11096.0001802451. Note that the first 3 decimals coincide. The cubic root of 123121220 is about 497.4823036895.

Adding to 123121220 its reverse (22121321), we get a palindrome (145242541).

The spelling of 123121220 in words is "one hundred twenty-three million, one hundred twenty-one thousand, two hundred twenty".