2666665728 has 108 divisors (see below), whose sum is σ = 7704019960. Its totient is φ = 887113728.

The previous prime is 2666665721. The next prime is 2666665759. The reversal of 2666665728 is 8275666662.

It is a happy number.

It is a super-2 number, since 2×2666665728² = 14222212209779539968, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2666665721) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1688043 + ... + 1689621.

Almost surely, 2^2666665728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2666665728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3852009980).

2666665728 is an abundant number, since it is smaller than the sum of its proper divisors (5037354232).

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

2666665728 is a wasteful number, since it uses less digits than its factorization.

2666665728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2334 (or 2317 counting only the distinct ones).

The product of its digits is 8709120, while the sum is 54.

The square root of 2666665728 is about 51639.7688608305. The cubic root of 2666665728 is about 1386.7223859925.

The spelling of 2666665728 in words is "two billion, six hundred sixty-six million, six hundred sixty-five thousand, seven hundred twenty-eight".