123531728 has 20 divisors (see below), whose sum is σ = 240953700. Its totient is φ = 61350144.

The previous prime is 123531721. The next prime is 123531739. The reversal of 123531728 is 827135321.

It can be written as a sum of positive squares in 2 ways, for example, as 28430224 + 95101504 = 5332^2 + 9752^2 .

It is a junction number, because it is equal to n+sod(n) for n = 123531694 and 123531703.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123531721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23525 + ... + 28292.

It is an arithmetic number, because the mean of its divisors is an integer number (12047685).

Almost surely, 2^123531728 is an apocalyptic number.

It is an amenable number.

123531728 is a deficient number, since it is larger than the sum of its proper divisors (117421972).

123531728 is a wasteful number, since it uses less digits than its factorization.

123531728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51974 (or 51968 counting only the distinct ones).

The product of its digits is 10080, while the sum is 32.

The square root of 123531728 is about 11114.4828039815. The cubic root of 123531728 is about 498.0345884375.

The spelling of 123531728 in words is "one hundred twenty-three million, five hundred thirty-one thousand, seven hundred twenty-eight".