665918928 has 80 divisors (see below), whose sum is σ = 1914778240. Its totient is φ = 221584896.

The previous prime is 665918923. The next prime is 665918987. The reversal of 665918928 is 829819566.

It is a happy number.

665918928 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665918923) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 354600 + ... + 356472.

It is an arithmetic number, because the mean of its divisors is an integer number (23934728).

Almost surely, 2^665918928 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 665918928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (957389120).

665918928 is an abundant number, since it is smaller than the sum of its proper divisors (1248859312).

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

665918928 is a wasteful number, since it uses less digits than its factorization.

665918928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2713 (or 2701 counting only the distinct ones).

The product of its digits is 1866240, while the sum is 54.

The square root of 665918928 is about 25805.4050152289. The cubic root of 665918928 is about 873.2537376066.

The spelling of 665918928 in words is "six hundred sixty-five million, nine hundred eighteen thousand, nine hundred twenty-eight".