665556611 has 8 divisors (see below), whose sum is σ = 668438400. Its totient is φ = 662681088.

The previous prime is 665556601. The next prime is 665556637. The reversal of 665556611 is 116655566.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665556611 is a prime.

It is a Duffinian number.

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (665556601) 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, 423950 + ... + 425516.

It is an arithmetic number, because the mean of its divisors is an integer number (83554800).

Almost surely, 2^665556611 is an apocalyptic number.

665556611 is a deficient number, since it is larger than the sum of its proper divisors (2881789).

665556611 is a wasteful number, since it uses less digits than its factorization.

665556611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3133.

The product of its digits is 162000, while the sum is 41.

The square root of 665556611 is about 25798.3838834916. The cubic root of 665556611 is about 873.0953339029.

The spelling of 665556611 in words is "six hundred sixty-five million, five hundred fifty-six thousand, six hundred eleven".