3666561601 has 4 divisors (see below), whose sum is σ = 3671497152. Its totient is φ = 3661626052.

The previous prime is 3666561593. The next prime is 3666561631. The reversal of 3666561601 is 1061656663.

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.

It is a cyclic number.

It is not a de Polignac number, because 3666561601 - 2³ = 3666561593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3666561631) 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, 2466661 + ... + 2468146.

It is an arithmetic number, because the mean of its divisors is an integer number (917874288).

Almost surely, 2^3666561601 is an apocalyptic number.

It is an amenable number.

3666561601 is a deficient number, since it is larger than the sum of its proper divisors (4935551).

3666561601 is an equidigital number, since it uses as much as digits as its factorization.

3666561601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4935550.

The product of its (nonzero) digits is 116640, while the sum is 40.

The square root of 3666561601 is about 60552.1395245453. The cubic root of 3666561601 is about 1542.0069410837.

The spelling of 3666561601 in words is "three billion, six hundred sixty-six million, five hundred sixty-one thousand, six hundred one".