5555505661 has 4 divisors (see below), whose sum is σ = 5563024000. Its totient is φ = 5547987324.

The previous prime is 5555505619. The next prime is 5555505719. The reversal of 5555505661 is 1665055555.

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 5555505661 - 2⁷ = 5555505533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5555505601) 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, 3758061 + ... + 3759538.

It is an arithmetic number, because the mean of its divisors is an integer number (1390756000).

Almost surely, 2^5555505661 is an apocalyptic number.

It is an amenable number.

5555505661 is a deficient number, since it is larger than the sum of its proper divisors (7518339).

5555505661 is an equidigital number, since it uses as much as digits as its factorization.

5555505661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7518338.

The product of its (nonzero) digits is 562500, while the sum is 43.

The square root of 5555505661 is about 74535.2645463877. The cubic root of 5555505661 is about 1771.0923132008.

The spelling of 5555505661 in words is "five billion, five hundred fifty-five million, five hundred five thousand, six hundred sixty-one".