3681055561 has 4 divisors (see below), whose sum is σ = 3725405712. Its totient is φ = 3636705412.

The previous prime is 3681055559. The next prime is 3681055589. The reversal of 3681055561 is 1655501863.

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 3681055561 - 2¹ = 3681055559 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3681055531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22174951 + ... + 22175116.

It is an arithmetic number, because the mean of its divisors is an integer number (931351428).

Almost surely, 2^3681055561 is an apocalyptic number.

It is an amenable number.

3681055561 is a deficient number, since it is larger than the sum of its proper divisors (44350151).

3681055561 is an equidigital number, since it uses as much as digits as its factorization.

3681055561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44350150.

The product of its (nonzero) digits is 108000, while the sum is 40.

The square root of 3681055561 is about 60671.7031325147. The cubic root of 3681055561 is about 1544.0361266626.

The spelling of 3681055561 in words is "three billion, six hundred eighty-one million, fifty-five thousand, five hundred sixty-one".