665123424 has 192 divisors, whose sum is σ = 2123573760. Its totient is φ = 178053120.

The previous prime is 665123413. The next prime is 665123429. The reversal of 665123424 is 424321566.

665123424 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665123429) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1442554 + ... + 1443014.

It is an arithmetic number, because the mean of its divisors is an integer number (11060280).

Almost surely, 2^665123424 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665123424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1061786880).

665123424 is an abundant number, since it is smaller than the sum of its proper divisors (1458450336).

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

665123424 is a wasteful number, since it uses less digits than its factorization.

665123424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 613 (or 605 counting only the distinct ones).

The product of its digits is 34560, while the sum is 33.

The square root of 665123424 is about 25789.9868941417. The cubic root of 665123424 is about 872.9058706140.

The spelling of 665123424 in words is "six hundred sixty-five million, one hundred twenty-three thousand, four hundred twenty-four".