6605666001 has 18 divisors (see below), whose sum is σ = 10487785490. Its totient is φ = 4003433280.

The previous prime is 6605665993. The next prime is 6605666017. The reversal of 6605666001 is 1006665066.

It can be written as a sum of positive squares in only one way, i.e., 6272640000 + 333026001 = 79200^2 + 18249^2 .

It is not a de Polignac number, because 6605666001 - 2³ = 6605665993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6605666101) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 3031816 + ... + 3033993.

Almost surely, 2^6605666001 is an apocalyptic number.

It is an amenable number.

6605666001 is a deficient number, since it is larger than the sum of its proper divisors (3882119489).

6605666001 is a wasteful number, since it uses less digits than its factorization.

6605666001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6065837 (or 6065823 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 6605666001 is about 81275.2483908847. The cubic root of 6605666001 is about 1876.3140774384.

It can be divided in two parts, 660 and 5666001, that added together give a triangular number (5666661 = T₃₃₆₆).

The spelling of 6605666001 in words is "six billion, six hundred five million, six hundred sixty-six thousand, one".