123403840 has 112 divisors (see below), whose sum is σ = 340156800. Its totient is φ = 41766912.

The previous prime is 123403831. The next prime is 123403859. The reversal of 123403840 is 48304321.

It is a tau number, because it is divible by the number of its divisors (112).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 199051 + ... + 199669.

Almost surely, 2^123403840 is an apocalyptic number.

123403840 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 123403840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (170078400).

123403840 is an abundant number, since it is smaller than the sum of its proper divisors (216752960).

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

123403840 is an equidigital number, since it uses as much as digits as its factorization.

123403840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 732 (or 722 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 123403840 is about 11108.7281000122. The cubic root of 123403840 is about 497.8626632685.

The spelling of 123403840 in words is "one hundred twenty-three million, four hundred three thousand, eight hundred forty".