5555556661 has 8 divisors (see below), whose sum is σ = 5849278400. Its totient is φ = 5261967360.

The previous prime is 5555556659. The next prime is 5555556683. The reversal of 5555556661 is 1666555555.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 5555556661 - 2¹ = 5555556659 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 (5555556641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59701 + ... + 121141.

It is an arithmetic number, because the mean of its divisors is an integer number (731159800).

Almost surely, 2^5555556661 is an apocalyptic number.

It is an amenable number.

5555556661 is a deficient number, since it is larger than the sum of its proper divisors (293721739).

5555556661 is a wasteful number, since it uses less digits than its factorization.

5555556661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66219.

The product of its digits is 3375000, while the sum is 49.

The square root of 5555556661 is about 74535.6066655394. The cubic root of 5555556661 is about 1771.0977327753.

The spelling of 5555556661 in words is "five billion, five hundred fifty-five million, five hundred fifty-six thousand, six hundred sixty-one".