123661440 has 192 divisors, whose sum is σ = 488180160. Its totient is φ = 28256256.

The previous prime is 123661429. The next prime is 123661441. The reversal of 123661440 is 44166321.

123661440 is a `hidden beast` number, since 1 + 2 + 3 + 6 + 614 + 40 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (123661441) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 38787 + ... + 41853.

It is an arithmetic number, because the mean of its divisors is an integer number (2542605).

Almost surely, 2^123661440 is an apocalyptic number.

123661440 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 123661440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (244090080).

123661440 is an abundant number, since it is smaller than the sum of its proper divisors (364518720).

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

123661440 is a wasteful number, since it uses less digits than its factorization.

123661440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3099 (or 3084 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 123661440 is about 11120.3165422572. The cubic root of 123661440 is about 498.2088445194.

The spelling of 123661440 in words is "one hundred twenty-three million, six hundred sixty-one thousand, four hundred forty".