2651665 has 4 divisors (see below), whose sum is σ = 3182004. Its totient is φ = 2121328.

The previous prime is 2651651. The next prime is 2651669. The reversal of 2651665 is 5661562.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5661562 = 2 ⋅2830781.

It can be written as a sum of positive squares in 2 ways, for example, as 508369 + 2143296 = 713^2 + 1464^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2651665 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2651669) 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, 265162 + ... + 265171.

It is an arithmetic number, because the mean of its divisors is an integer number (795501).

2^2651665 is an apocalyptic number.

It is an amenable number.

2651665 is a deficient number, since it is larger than the sum of its proper divisors (530339).

2651665 is an equidigital number, since it uses as much as digits as its factorization.

2651665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 530338.

The product of its digits is 10800, while the sum is 31.

The square root of 2651665 is about 1628.3933799915. The cubic root of 2651665 is about 138.4117263445.

The spelling of 2651665 in words is "two million, six hundred fifty-one thousand, six hundred sixty-five".