665946609701 has 4 divisors (see below), whose sum is σ = 665948841504. Its totient is φ = 665944377900.

The previous prime is 665946609673. The next prime is 665946609709. The reversal of 665946609701 is 107906649566.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665946609701 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665946609709) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 583715 + ... + 1293296.

It is an arithmetic number, because the mean of its divisors is an integer number (166487210376).

Almost surely, 2^665946609701 is an apocalyptic number.

It is an amenable number.

665946609701 is a deficient number, since it is larger than the sum of its proper divisors (2231803).

665946609701 is a wasteful number, since it uses less digits than its factorization.

665946609701 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2231802.

The product of its (nonzero) digits is 14696640, while the sum is 59.

The spelling of 665946609701 in words is "six hundred sixty-five billion, nine hundred forty-six million, six hundred nine thousand, seven hundred one".