3565661 has 4 divisors (see below), whose sum is σ = 3889824. Its totient is φ = 3241500.

The previous prime is 3565619. The next prime is 3565669. The reversal of 3565661 is 1665653.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1665653 = 11 ⋅151423.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3565661 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3565669) 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, 162065 + ... + 162086.

It is an arithmetic number, because the mean of its divisors is an integer number (972456).

Almost surely, 2^3565661 is an apocalyptic number.

It is an amenable number.

3565661 is a deficient number, since it is larger than the sum of its proper divisors (324163).

3565661 is a wasteful number, since it uses less digits than its factorization.

3565661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 324162.

The product of its digits is 16200, while the sum is 32.

The square root of 3565661 is about 1888.2957925071. The cubic root of 3565661 is about 152.7730269768.

The spelling of 3565661 in words is "three million, five hundred sixty-five thousand, six hundred sixty-one".