66555800855566 has 16 divisors (see below), whose sum is σ = 109908661967280. Its totient is φ = 29975089625280.

The previous prime is 66555800855497. The next prime is 66555800855581.

66555800855566 is nontrivially palindromic in base 10.

It is a super-3 number, since 3×66555800855566³ (a number of 42 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66555800855495 and 66555800855504.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13877353911 + ... + 13877358706.

It is an arithmetic number, because the mean of its divisors is an integer number (6869291372955).

Almost surely, 2^{66555800855566} is an apocalyptic number.

66555800855566 is a deficient number, since it is larger than the sum of its proper divisors (43352861111714).

66555800855566 is a wasteful number, since it uses less digits than its factorization.

66555800855566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27754712739.

The product of its (nonzero) digits is 1296000000, while the sum is 70.

The spelling of 66555800855566 in words is "sixty-six trillion, five hundred fifty-five billion, eight hundred million, eight hundred fifty-five thousand, five hundred sixty-six".