665445040 has 40 divisors (see below), whose sum is σ = 1666174608. Its totient is φ = 245702400.

The previous prime is 665444987. The next prime is 665445041. The reversal of 665445040 is 40544566.

665445040 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 665444987 and 665445005.

It is not an unprimeable number, because it can be changed into a prime (665445041) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 318886 + ... + 320965.

Almost surely, 2^665445040 is an apocalyptic number.

It is an amenable number.

665445040 is an abundant number, since it is smaller than the sum of its proper divisors (1000729568).

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

665445040 is a wasteful number, since it uses less digits than its factorization.

665445040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 639877 (or 639871 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 34.

The square root of 665445040 is about 25796.2214287287. The cubic root of 665445040 is about 873.0465438818.

The spelling of 665445040 in words is "six hundred sixty-five million, four hundred forty-five thousand, forty".