3689645 has 4 divisors (see below), whose sum is σ = 4427580. Its totient is φ = 2951712.

The previous prime is 3689633. The next prime is 3689669. The reversal of 3689645 is 5469863.

3689645 = 1108² + 1109² + 1110².

3689645 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5469863 = 7 ⋅781409.

It can be written as a sum of positive squares in 2 ways, for example, as 499849 + 3189796 = 707^2 + 1786^2 .

It is a cyclic number.

It is not a de Polignac number, because 3689645 - 2¹⁶ = 3624109 is a prime.

It is a super-3 number, since 3×3689645³ (a number of 21 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 368960 + ... + 368969.

It is an arithmetic number, because the mean of its divisors is an integer number (1106895).

Almost surely, 2^3689645 is an apocalyptic number.

It is an amenable number.

3689645 is a deficient number, since it is larger than the sum of its proper divisors (737935).

3689645 is an equidigital number, since it uses as much as digits as its factorization.

3689645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 737934.

The product of its digits is 155520, while the sum is 41.

The square root of 3689645 is about 1920.8448661982. The cubic root of 3689645 is about 154.5236153999.

Adding to 3689645 its sum of digits (41), we get a triangular number (3689686 = T₂₇₁₆).

It can be divided in two parts, 3689 and 645, that added together give a palindrome (4334).

The spelling of 3689645 in words is "three million, six hundred eighty-nine thousand, six hundred forty-five".