2109817 has 4 divisors (see below), whose sum is σ = 2220880. Its totient is φ = 1998756.

The previous prime is 2109799. The next prime is 2109841. The reversal of 2109817 is 7189012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2109817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2109857) 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, 55503 + ... + 55540.

It is an arithmetic number, because the mean of its divisors is an integer number (555220).

2^2109817 is an apocalyptic number.

It is an amenable number.

2109817 is a deficient number, since it is larger than the sum of its proper divisors (111063).

2109817 is a wasteful number, since it uses less digits than its factorization.

2109817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111062.

The product of its (nonzero) digits is 1008, while the sum is 28.

The square root of 2109817 is about 1452.5209120698. The cubic root of 2109817 is about 128.2571531158.

It can be divided in two parts, 21098 and 17, that added together give a triangular number (21115 = T₂₀₅).

The spelling of 2109817 in words is "two million, one hundred nine thousand, eight hundred seventeen".