666577 has 4 divisors (see below), whose sum is σ = 701680. Its totient is φ = 631476.

The previous prime is 666559. The next prime is 666599. The reversal of 666577 is 775666.

666577 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 666577 - 2¹¹ = 664529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666527) 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, 17523 + ... + 17560.

It is an arithmetic number, because the mean of its divisors is an integer number (175420).

2⁶⁶⁶⁵⁷⁷ is an apocalyptic number.

It is an amenable number.

666577 is a deficient number, since it is larger than the sum of its proper divisors (35103).

666577 is a wasteful number, since it uses less digits than its factorization.

666577 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35102.

The product of its digits is 52920, while the sum is 37.

The square root of 666577 is about 816.4416696862. The cubic root of 666577 is about 87.3541297456.

The spelling of 666577 in words is "six hundred sixty-six thousand, five hundred seventy-seven".