55666212217 has 16 divisors (see below), whose sum is σ = 73054771200. Its totient is φ = 41093306640.

The previous prime is 55666212193. The next prime is 55666212247. The reversal of 55666212217 is 71221266655.

It is a cyclic number.

It is not a de Polignac number, because 55666212217 - 2⁷ = 55666212089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55666212247) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19023217 + ... + 19026142.

It is an arithmetic number, because the mean of its divisors is an integer number (4565923200).

Almost surely, 2^55666212217 is an apocalyptic number.

It is an amenable number.

55666212217 is a deficient number, since it is larger than the sum of its proper divisors (17388558983).

55666212217 is a wasteful number, since it uses less digits than its factorization.

55666212217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38049396.

The product of its digits is 302400, while the sum is 43.

The spelling of 55666212217 in words is "fifty-five billion, six hundred sixty-six million, two hundred twelve thousand, two hundred seventeen".