123200640 has 192 divisors, whose sum is σ = 432726840. Its totient is φ = 32292864.

The previous prime is 123200611. The next prime is 123200641. The reversal of 123200640 is 46002321.

It is a happy number.

123200640 is a `hidden beast` number, since 1 + 2 + 3 + 20 + 0 + 640 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 120297024 + 2903616 = 10968^2 + 1704^2 .

It is a tau number, because it is divible by the number of its divisors (192).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (123200641) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 420334 + ... + 420626.

Almost surely, 2^123200640 is an apocalyptic number.

123200640 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 123200640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (216363420).

123200640 is an abundant number, since it is smaller than the sum of its proper divisors (309526200).

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

123200640 is a wasteful number, since it uses less digits than its factorization.

123200640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 391 (or 376 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 123200640 is about 11099.5783703707. The cubic root of 123200640 is about 497.5892485692.

Adding to 123200640 its reverse (46002321), we get a palindrome (169202961).

The spelling of 123200640 in words is "one hundred twenty-three million, two hundred thousand, six hundred forty".