665128657201 has 12 divisors (see below), whose sum is σ = 682919558352. Its totient is φ = 647787703416.

The previous prime is 665128657181. The next prime is 665128657229. The reversal of 665128657201 is 102756821566.

It is not a de Polignac number, because 665128657201 - 2⁵ = 665128657169 is a prime.

It is a super-2 number, since 2×665128657201² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665128657241) 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 11 ways as a sum of consecutive naturals, for example, 123270 + ... + 1159936.

It is an arithmetic number, because the mean of its divisors is an integer number (56909963196).

Almost surely, 2^665128657201 is an apocalyptic number.

It is an amenable number.

665128657201 is a deficient number, since it is larger than the sum of its proper divisors (17790901151).

665128657201 is a wasteful number, since it uses less digits than its factorization.

665128657201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1037100 (or 1037057 counting only the distinct ones).

The product of its (nonzero) digits is 1209600, while the sum is 49.

The spelling of 665128657201 in words is "six hundred sixty-five billion, one hundred twenty-eight million, six hundred fifty-seven thousand, two hundred one".