2663665 has 4 divisors (see below), whose sum is σ = 3196404. Its totient is φ = 2130928.

The previous prime is 2663651. The next prime is 2663669. The reversal of 2663665 is 5663662.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1787569 + 876096 = 1337^2 + 936^2 .

It is a cyclic number.

It is not a de Polignac number, because 2663665 - 2⁹ = 2663153 is a prime.

It is a super-2 number, since 2×2663665² = 14190222464450, which contains 22 as substring.

It is a Duffinian number.

2663665 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 2663665.

It is not an unprimeable number, because it can be changed into a prime (2663669) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 266362 + ... + 266371.

It is an arithmetic number, because the mean of its divisors is an integer number (799101).

2^2663665 is an apocalyptic number.

It is an amenable number.

2663665 is a deficient number, since it is larger than the sum of its proper divisors (532739).

2663665 is an equidigital number, since it uses as much as digits as its factorization.

2663665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 532738.

The product of its digits is 38880, while the sum is 34.

The square root of 2663665 is about 1632.0738341141. The cubic root of 2663665 is about 138.6202043498.

It can be divided in two parts, 26 and 63665, that multiplied together give a triangular number (1655290 = T₁₈₁₉).

The spelling of 2663665 in words is "two million, six hundred sixty-three thousand, six hundred sixty-five".