665677 has 2 divisors, whose sum is σ = 665678. Its totient is φ = 665676.

The previous prime is 665659. The next prime is 665713. The reversal of 665677 is 776566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 481636 + 184041 = 694^2 + 429^2 .

It is a cyclic number.

It is not a de Polignac number, because 665677 - 2⁷ = 665549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332838 + 332839.

It is an arithmetic number, because the mean of its divisors is an integer number (332839).

2⁶⁶⁵⁶⁷⁷ is an apocalyptic number.

It is an amenable number.

665677 is a deficient number, since it is larger than the sum of its proper divisors (1).

665677 is an equidigital number, since it uses as much as digits as its factorization.

665677 is an evil number, because the sum of its binary digits is even.

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

The square root of 665677 is about 815.8903112551. The cubic root of 665677 is about 87.3147973921.

Subtracting 665677 from its reverse (776566), we obtain a square (110889 = 333²).

The spelling of 665677 in words is "six hundred sixty-five thousand, six hundred seventy-seven".