666271855 has 4 divisors (see below), whose sum is σ = 799526232. Its totient is φ = 533017480.

The previous prime is 666271849. The next prime is 666271861. The reversal of 666271855 is 558172666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 558172666 = 2 ⋅279086333.

It is an interprime number because it is at equal distance from previous prime (666271849) and next prime (666271861).

It is a de Polignac number, because none of the positive numbers 2^k-666271855 is a prime.

It is a Duffinian number.

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, 66627181 + ... + 66627190.

It is an arithmetic number, because the mean of its divisors is an integer number (199881558).

Almost surely, 2^666271855 is an apocalyptic number.

666271855 is a deficient number, since it is larger than the sum of its proper divisors (133254377).

666271855 is a wasteful number, since it uses less digits than its factorization.

666271855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133254376.

The product of its digits is 604800, while the sum is 46.

The square root of 666271855 is about 25812.2423473824. The cubic root of 666271855 is about 873.4079808029.

The spelling of 666271855 in words is "six hundred sixty-six million, two hundred seventy-one thousand, eight hundred fifty-five".