123431220 has 288 divisors, whose sum is σ = 457591680. Its totient is φ = 26542080.

The previous prime is 123431207. The next prime is 123431227. The reversal of 123431220 is 22134321.

123431220 is a `hidden beast` number, since 12 + 3 + 431 + 220 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 123431193 and 123431202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123431227) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 639444 + ... + 639636.

It is an arithmetic number, because the mean of its divisors is an integer number (1588860).

Almost surely, 2^123431220 is an apocalyptic number.

123431220 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 123431220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (228795840).

123431220 is an abundant number, since it is smaller than the sum of its proper divisors (334160460).

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

123431220 is a wasteful number, since it uses less digits than its factorization.

123431220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255 (or 250 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 123431220 is about 11109.9603959690. The cubic root of 123431220 is about 497.8994813331.

Adding to 123431220 its reverse (22134321), we get a palindrome (145565541).

The spelling of 123431220 in words is "one hundred twenty-three million, four hundred thirty-one thousand, two hundred twenty".