2003645 has 32 divisors (see below), whose sum is σ = 3041280. Its totient is φ = 1235520.

The previous prime is 2003641. The next prime is 2003647. The reversal of 2003645 is 5463002.

It is not a de Polignac number, because 2003645 - 2² = 2003641 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2003641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15230 + ... + 15360.

It is an arithmetic number, because the mean of its divisors is an integer number (95040).

2^2003645 is an apocalyptic number.

It is an amenable number.

2003645 is a deficient number, since it is larger than the sum of its proper divisors (1037635).

2003645 is a wasteful number, since it uses less digits than its factorization.

2003645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185.

The product of its (nonzero) digits is 720, while the sum is 20.

The square root of 2003645 is about 1415.5016778514. The cubic root of 2003645 is about 126.0685987421.

Adding to 2003645 its reverse (5463002), we get a palindrome (7466647).

It can be divided in two parts, 200364 and 5, that multiplied together give a triangular number (1001820 = T₁₄₁₅).

The spelling of 2003645 in words is "two million, three thousand, six hundred forty-five".