123543640 has 64 divisors (see below), whose sum is σ = 308448000. Its totient is φ = 44154240.

The previous prime is 123543631. The next prime is 123543647. The reversal of 123543640 is 46345321.

It is a junction number, because it is equal to n+sod(n) for n = 123543599 and 123543608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123543647) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23581 + ... + 28339.

It is an arithmetic number, because the mean of its divisors is an integer number (4819500).

Almost surely, 2^123543640 is an apocalyptic number.

123543640 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 123543640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (154224000).

123543640 is an abundant number, since it is smaller than the sum of its proper divisors (184904360).

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

123543640 is a wasteful number, since it uses less digits than its factorization.

123543640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4840 (or 4836 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 28.

The square root of 123543640 is about 11115.0186684504. The cubic root of 123543640 is about 498.0505961937.

Adding to 123543640 its reverse (46345321), we get a palindrome (169888961).

The spelling of 123543640 in words is "one hundred twenty-three million, five hundred forty-three thousand, six hundred forty".