2099605 has 4 divisors (see below), whose sum is σ = 2519532. Its totient is φ = 1679680.

The previous prime is 2099593. The next prime is 2099611. The reversal of 2099605 is 5069902.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5069902 = 2 ⋅2534951.

It can be written as a sum of positive squares in 2 ways, for example, as 758641 + 1340964 = 871^2 + 1158^2 .

It is not a de Polignac number, because 2099605 - 2⁷ = 2099477 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 209956 + ... + 209965.

It is an arithmetic number, because the mean of its divisors is an integer number (629883).

2^2099605 is an apocalyptic number.

It is an amenable number.

2099605 is a deficient number, since it is larger than the sum of its proper divisors (419927).

2099605 is an equidigital number, since it uses as much as digits as its factorization.

2099605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 419926.

The product of its (nonzero) digits is 4860, while the sum is 31.

The square root of 2099605 is about 1449.0013802616. The cubic root of 2099605 is about 128.0498869672.

It can be divided in two parts, 2099 and 605, that added together give a square (2704 = 52²).

The spelling of 2099605 in words is "two million, ninety-nine thousand, six hundred five".