665423878533120 has 3120 divisors, whose sum is σ = 2896372485534528. Its totient is φ = 143132306964480.

The previous prime is 665423878533107. The next prime is 665423878533121. The reversal of 665423878533120 is 21335878324566.

665423878533120 is a `hidden beast` number, since 6 + 6 + 5 + 4 + 2 + 3 + 8 + 78 + 533 + 1 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (665423878533121) by changing a digit.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 758750146122 + ... + 758750146998.

Almost surely, 2^{665423878533120} is an apocalyptic number.

665423878533120 is a gapful number since it is divisible by the number (60) 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 665423878533120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1448186242767264).

665423878533120 is an abundant number, since it is smaller than the sum of its proper divisors (2230948607001408).

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

665423878533120 is a wasteful number, since it uses less digits than its factorization.

665423878533120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1144 (or 1094 counting only the distinct ones).

The product of its (nonzero) digits is 174182400, while the sum is 63.

The spelling of 665423878533120 in words is "six hundred sixty-five trillion, four hundred twenty-three billion, eight hundred seventy-eight million, five hundred thirty-three thousand, one hundred twenty".