6655551661 has 8 divisors (see below), whose sum is σ = 7261380000. Its totient is φ = 6049853040.

The previous prime is 6655551659. The next prime is 6655551671. The reversal of 6655551661 is 1661555566.

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

It is not a de Polignac number, because 6655551661 - 2¹ = 6655551659 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 (6655551611) 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 7 ways as a sum of consecutive naturals, for example, 97515 + ... + 151063.

It is an arithmetic number, because the mean of its divisors is an integer number (907672500).

Almost surely, 2^6655551661 is an apocalyptic number.

It is an amenable number.

6655551661 is a deficient number, since it is larger than the sum of its proper divisors (605828339).

6655551661 is a wasteful number, since it uses less digits than its factorization.

6655551661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64859.

The product of its digits is 810000, while the sum is 46.

The square root of 6655551661 is about 81581.5644677154. The cubic root of 6655551661 is about 1881.0255138500.

The spelling of 6655551661 in words is "six billion, six hundred fifty-five million, five hundred fifty-one thousand, six hundred sixty-one".