2105645 has 8 divisors (see below), whose sum is σ = 2536056. Its totient is φ = 1678336.

The previous prime is 2105641. The next prime is 2105669. The reversal of 2105645 is 5465012.

It can be written as a sum of positive squares in 4 ways, for example, as 162409 + 1943236 = 403^2 + 1394^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2105645 - 2² = 2105641 is a prime.

It is a super-3 number, since 3×2105645³ = 28007652857523633375, which contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2105645.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2105641) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 1169 + ... + 2361.

It is an arithmetic number, because the mean of its divisors is an integer number (317007).

2^2105645 is an apocalyptic number.

It is an amenable number.

2105645 is a deficient number, since it is larger than the sum of its proper divisors (430411).

2105645 is a wasteful number, since it uses less digits than its factorization.

2105645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1551.

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 2105645 is about 1451.0840775089. The cubic root of 2105645 is about 128.1725577963.

The spelling of 2105645 in words is "two million, one hundred five thousand, six hundred forty-five".