666606055 has 4 divisors (see below), whose sum is σ = 799927272. Its totient is φ = 533284840.

The previous prime is 666606047. The next prime is 666606067. The reversal of 666606055 is 550606666.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 550606666 = 2 ⋅275303333.

It is not a de Polignac number, because 666606055 - 2³ = 666606047 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 666605999 and 666606017.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66660601 + ... + 66660610.

It is an arithmetic number, because the mean of its divisors is an integer number (199981818).

Almost surely, 2^666606055 is an apocalyptic number.

666606055 is a deficient number, since it is larger than the sum of its proper divisors (133321217).

666606055 is a wasteful number, since it uses less digits than its factorization.

666606055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133321216.

The product of its (nonzero) digits is 194400, while the sum is 40.

The square root of 666606055 is about 25818.7152081586. The cubic root of 666606055 is about 873.5539893500.

The spelling of 666606055 in words is "six hundred sixty-six million, six hundred six thousand, fifty-five".