665666125 has 16 divisors (see below), whose sum is σ = 833002560. Its totient is φ = 531090000.

The previous prime is 665666077. The next prime is 665666129. The reversal of 665666125 is 521666566.

665666125 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 665666125 - 2⁷ = 665665997 is a prime.

It is a super-2 number, since 2×665666125² = 886222779945031250, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665666129) 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, 40350 + ... + 54400.

It is an arithmetic number, because the mean of its divisors is an integer number (52062660).

Almost surely, 2^665666125 is an apocalyptic number.

It is an amenable number.

665666125 is a deficient number, since it is larger than the sum of its proper divisors (167336435).

665666125 is a wasteful number, since it uses less digits than its factorization.

665666125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14445 (or 14435 counting only the distinct ones).

The product of its digits is 388800, while the sum is 43.

The square root of 665666125 is about 25800.5062934819. The cubic root of 665666125 is about 873.1432190950.

The spelling of 665666125 in words is "six hundred sixty-five million, six hundred sixty-six thousand, one hundred twenty-five".