665580901 has 8 divisors (see below), whose sum is σ = 691808544. Its totient is φ = 639786960.

The previous prime is 665580899. The next prime is 665580907. The reversal of 665580901 is 109085566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 665580901 - 2¹ = 665580899 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665580907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 105295 + ... + 111436.

It is an arithmetic number, because the mean of its divisors is an integer number (86476068).

Almost surely, 2^665580901 is an apocalyptic number.

It is an amenable number.

665580901 is a deficient number, since it is larger than the sum of its proper divisors (26227643).

665580901 is a wasteful number, since it uses less digits than its factorization.

665580901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216851.

The product of its (nonzero) digits is 64800, while the sum is 40.

The square root of 665580901 is about 25798.8546451194. The cubic root of 665580901 is about 873.1059552021.

The spelling of 665580901 in words is "six hundred sixty-five million, five hundred eighty thousand, nine hundred one".