2666397709 has 8 divisors (see below), whose sum is σ = 2688140088. Its totient is φ = 2644688640.

The previous prime is 2666397703. The next prime is 2666397733. The reversal of 2666397709 is 9077936662.

It can be written as a sum of positive squares in 4 ways, for example, as 1033429609 + 1632968100 = 32147^2 + 40410^2 .

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 2666397709 - 2⁷ = 2666397581 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2666397709.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2666397703) 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, 167329 + ... + 182569.

It is an arithmetic number, because the mean of its divisors is an integer number (336017511).

Almost surely, 2^2666397709 is an apocalyptic number.

It is an amenable number.

2666397709 is a deficient number, since it is larger than the sum of its proper divisors (21742379).

2666397709 is a wasteful number, since it uses less digits than its factorization.

2666397709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16655.

The product of its (nonzero) digits is 5143824, while the sum is 55.

The square root of 2666397709 is about 51637.1737123557. The cubic root of 2666397709 is about 1386.6759259262.

The spelling of 2666397709 in words is "two billion, six hundred sixty-six million, three hundred ninety-seven thousand, seven hundred nine".