123539640 has 128 divisors (see below), whose sum is σ = 430686720. Its totient is φ = 27763200.

The previous prime is 123539639. The next prime is 123539659. The reversal of 123539640 is 46935321.

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 31 ways as a sum of consecutive naturals, for example, 50035 + ... + 52445.

It is an arithmetic number, because the mean of its divisors is an integer number (3364740).

Almost surely, 2^123539640 is an apocalyptic number.

123539640 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 123539640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (215343360).

123539640 is an abundant number, since it is smaller than the sum of its proper divisors (307147080).

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

123539640 is a wasteful number, since it uses less digits than its factorization.

123539640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2493 (or 2489 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 33.

The square root of 123539640 is about 11114.8387302740. The cubic root of 123539640 is about 498.0452209706.

The spelling of 123539640 in words is "one hundred twenty-three million, five hundred thirty-nine thousand, six hundred forty".