2666638891664 has 40 divisors (see below), whose sum is σ = 5692109967360. Its totient is φ = 1200107504000.

The previous prime is 2666638891633. The next prime is 2666638891667. The reversal of 2666638891664 is 4661988366662.

It is a super-2 number, since 2×2666638891664² (a number of 26 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2666638891667) 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, 74988944 + ... + 75024495.

It is an arithmetic number, because the mean of its divisors is an integer number (142302749184).

Almost surely, 2^{2666638891664} is an apocalyptic number.

It is an amenable number.

2666638891664 is an abundant number, since it is smaller than the sum of its proper divisors (3025471075696).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2666638891664 is a wasteful number, since it uses less digits than its factorization.

2666638891664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150013559 (or 150013553 counting only the distinct ones).

The product of its digits is 644972544, while the sum is 71.

The spelling of 2666638891664 in words is "two trillion, six hundred sixty-six billion, six hundred thirty-eight million, eight hundred ninety-one thousand, six hundred sixty-four".