665777 has 4 divisors (see below), whose sum is σ = 760896. Its totient is φ = 570660.

The previous prime is 665773. The next prime is 665783. The reversal of 665777 is 777566.

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 665777 - 2² = 665773 is a prime.

It is a Duffinian number.

665777 is a modest number, since divided by 777 gives 665 as remainder.

It is a self number, because there is not a number n which added to its sum of digits gives 665777.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 665777.

It is not an unprimeable number, because it can be changed into a prime (665773) 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, 47549 + ... + 47562.

It is an arithmetic number, because the mean of its divisors is an integer number (190224).

2⁶⁶⁵⁷⁷⁷ is an apocalyptic number.

It is an amenable number.

665777 is a deficient number, since it is larger than the sum of its proper divisors (95119).

665777 is an equidigital number, since it uses as much as digits as its factorization.

665777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95118.

The product of its digits is 61740, while the sum is 38.

The square root of 665777 is about 815.9515917014. The cubic root of 665777 is about 87.3191694037.

The spelling of 665777 in words is "six hundred sixty-five thousand, seven hundred seventy-seven".