666871441 has 4 divisors (see below), whose sum is σ = 667310832. Its totient is φ = 666432052.

The previous prime is 666871409. The next prime is 666871463. The reversal of 666871441 is 144178666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 666871441 - 2⁵ = 666871409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666871141) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 217411 + ... + 220456.

It is an arithmetic number, because the mean of its divisors is an integer number (166827708).

Almost surely, 2^666871441 is an apocalyptic number.

It is an amenable number.

666871441 is a deficient number, since it is larger than the sum of its proper divisors (439391).

666871441 is a wasteful number, since it uses less digits than its factorization.

666871441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 439390.

The product of its digits is 193536, while the sum is 43.

The square root of 666871441 is about 25823.8541081691. The cubic root of 666871441 is about 873.6698990086.

The spelling of 666871441 in words is "six hundred sixty-six million, eight hundred seventy-one thousand, four hundred forty-one".