123312640 has 160 divisors (see below), whose sum is σ = 335871360. Its totient is φ = 43008000.

The previous prime is 123312583. The next prime is 123312643. The reversal of 123312640 is 46213321.

It is a tau number, because it is divible by the number of its divisors (160).

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (123312643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 816565 + ... + 816715.

It is an arithmetic number, because the mean of its divisors is an integer number (2099196).

Almost surely, 2^123312640 is an apocalyptic number.

123312640 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 123312640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (167935680).

123312640 is an abundant number, since it is smaller than the sum of its proper divisors (212558720).

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

123312640 is a wasteful number, since it uses less digits than its factorization.

123312640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214 (or 198 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 123312640 is about 11104.6224609394. The cubic root of 123312640 is about 497.7399867379.

Adding to 123312640 its reverse (46213321), we get a palindrome (169525961).

The spelling of 123312640 in words is "one hundred twenty-three million, three hundred twelve thousand, six hundred forty".