66555455566 has 48 divisors (see below), whose sum is σ = 111869228160. Its totient is φ = 29608951680.

The previous prime is 66555455563. The next prime is 66555455573.

It is a happy number.

66555455566 is nontrivially palindromic in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 66555455566.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66555455563) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5385991 + ... + 5398333.

It is an arithmetic number, because the mean of its divisors is an integer number (2330608920).

Almost surely, 2^66555455566 is an apocalyptic number.

66555455566 is a deficient number, since it is larger than the sum of its proper divisors (45313772594).

66555455566 is a wasteful number, since it uses less digits than its factorization.

66555455566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12889 (or 12872 counting only the distinct ones).

The product of its digits is 81000000, while the sum is 58.

The spelling of 66555455566 in words is "sixty-six billion, five hundred fifty-five million, four hundred fifty-five thousand, five hundred sixty-six".