2666521872065 has 16 divisors (see below), whose sum is σ = 3221372306880. Its totient is φ = 2118880643520.

The previous prime is 2666521872023. The next prime is 2666521872097. The reversal of 2666521872065 is 5602781256662.

It is a happy number.

It is not a de Polignac number, because 2666521872065 - 2²⁰ = 2666520823489 is a prime.

It is a super-2 number, since 2×2666521872065² (a number of 26 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 2666521872065.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 913691 + ... + 2483520.

It is an arithmetic number, because the mean of its divisors is an integer number (201335769180).

Almost surely, 2^{2666521872065} is an apocalyptic number.

It is an amenable number.

2666521872065 is a deficient number, since it is larger than the sum of its proper divisors (554850434815).

2666521872065 is a wasteful number, since it uses less digits than its factorization.

2666521872065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3398272.

The product of its (nonzero) digits is 14515200, while the sum is 56.

The spelling of 2666521872065 in words is "two trillion, six hundred sixty-six billion, five hundred twenty-one million, eight hundred seventy-two thousand, sixty-five".