123542640 has 240 divisors, whose sum is σ = 455783328. Its totient is φ = 29804544.

The previous prime is 123542623. The next prime is 123542641. The reversal of 123542640 is 46245321.

123542640 is a `hidden beast` number, since 1 + 235 + 426 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123542641) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 627022 + ... + 627218.

Almost surely, 2^123542640 is an apocalyptic number.

123542640 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 123542640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (227891664).

123542640 is an abundant number, since it is smaller than the sum of its proper divisors (332240688).

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

123542640 is a wasteful number, since it uses less digits than its factorization.

123542640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 296 (or 287 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 123542640 is about 11114.9736841794. The cubic root of 123542640 is about 498.0492523988.

Adding to 123542640 its reverse (46245321), we get a palindrome (169787961).

The spelling of 123542640 in words is "one hundred twenty-three million, five hundred forty-two thousand, six hundred forty".