2820665 has 4 divisors (see below), whose sum is σ = 3384804. Its totient is φ = 2256528.

The previous prime is 2820641. The next prime is 2820667. The reversal of 2820665 is 5660282.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5660282 = 2 ⋅2830141.

It can be written as a sum of positive squares in 2 ways, for example, as 1530169 + 1290496 = 1237^2 + 1136^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2820665 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2820667) 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, 282062 + ... + 282071.

It is an arithmetic number, because the mean of its divisors is an integer number (846201).

2^2820665 is an apocalyptic number.

It is an amenable number.

2820665 is a deficient number, since it is larger than the sum of its proper divisors (564139).

2820665 is an equidigital number, since it uses as much as digits as its factorization.

2820665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 564138.

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 2820665 is about 1679.4835515717. The cubic root of 2820665 is about 141.2918689675.

The spelling of 2820665 in words is "two million, eight hundred twenty thousand, six hundred sixty-five".