665025444 has 96 divisors (see below), whose sum is σ = 1785168000. Its totient is φ = 213954048.

The previous prime is 665025421. The next prime is 665025461. The reversal of 665025444 is 444520566.

665025444 is a `hidden beast` number, since 66 + 50 + 2 + 544 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 665025399 and 665025408.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 412512 + ... + 414120.

It is an arithmetic number, because the mean of its divisors is an integer number (18595500).

Almost surely, 2^665025444 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 665025444, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (892584000).

665025444 is an abundant number, since it is smaller than the sum of its proper divisors (1120142556).

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

665025444 is a wasteful number, since it uses less digits than its factorization.

665025444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1754 (or 1746 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 36.

The square root of 665025444 is about 25788.0872497361. The cubic root of 665025444 is about 872.8630056288.

The spelling of 665025444 in words is "six hundred sixty-five million, twenty-five thousand, four hundred forty-four".