2665681 has 8 divisors (see below), whose sum is σ = 2821280. Its totient is φ = 2511648.

The previous prime is 2665669. The next prime is 2665687. The reversal of 2665681 is 1865662.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-2665681 is a prime.

It is a super-2 number, since 2×2665681² = 14211710387522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2665687) 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, 5605 + ... + 6061.

It is an arithmetic number, because the mean of its divisors is an integer number (352660).

2^2665681 is an apocalyptic number.

It is an amenable number.

2665681 is a deficient number, since it is larger than the sum of its proper divisors (155599).

2665681 is a wasteful number, since it uses less digits than its factorization.

2665681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 783.

The product of its digits is 17280, while the sum is 34.

The square root of 2665681 is about 1632.6913364136. The cubic root of 2665681 is about 138.6551671872.

The spelling of 2665681 in words is "two million, six hundred sixty-five thousand, six hundred eighty-one".