3666604561 has 16 divisors (see below), whose sum is σ = 3773972736. Its totient is φ = 3560588416.

The previous prime is 3666604549. The next prime is 3666604663. The reversal of 3666604561 is 1654066663.

3666604561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 3666604561 - 2⁷ = 3666604433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3666604541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5942325 + ... + 5942941.

It is an arithmetic number, because the mean of its divisors is an integer number (235873296).

Almost surely, 2^3666604561 is an apocalyptic number.

It is an amenable number.

3666604561 is a deficient number, since it is larger than the sum of its proper divisors (107368175).

3666604561 is a wasteful number, since it uses less digits than its factorization.

3666604561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1448.

The product of its (nonzero) digits is 466560, while the sum is 43.

The square root of 3666604561 is about 60552.4942591137. The cubic root of 3666604561 is about 1542.0129634708.

The spelling of 3666604561 in words is "three billion, six hundred sixty-six million, six hundred four thousand, five hundred sixty-one".