2190665 has 4 divisors (see below), whose sum is σ = 2628804. Its totient is φ = 1752528.

The previous prime is 2190653. The next prime is 2190679. The reversal of 2190665 is 5660912.

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 405769 + 1784896 = 637^2 + 1336^2 .

It is a cyclic number.

It is not a de Polignac number, because 2190665 - 2¹⁴ = 2174281 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 219062 + ... + 219071.

It is an arithmetic number, because the mean of its divisors is an integer number (657201).

2^2190665 is an apocalyptic number.

It is an amenable number.

2190665 is a deficient number, since it is larger than the sum of its proper divisors (438139).

2190665 is an equidigital number, since it uses as much as digits as its factorization.

2190665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 438138.

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 2190665 is about 1480.0895243194. The cubic root of 2190665 is about 129.8749290194.

The spelling of 2190665 in words is "two million, one hundred ninety thousand, six hundred sixty-five".