665629 has 2 divisors, whose sum is σ = 665630. Its totient is φ = 665628.

The previous prime is 665617. The next prime is 665633. The reversal of 665629 is 926566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 357604 + 308025 = 598^2 + 555^2 .

It is a cyclic number.

It is not a de Polignac number, because 665629 - 2⁷ = 665501 is a prime.

665629 is a lucky number.

It is equal to p₅₃₉₉₈ and since 665629 and 53998 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 665594 and 665603.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332814 + 332815.

It is an arithmetic number, because the mean of its divisors is an integer number (332815).

2⁶⁶⁵⁶²⁹ is an apocalyptic number.

It is an amenable number.

665629 is a deficient number, since it is larger than the sum of its proper divisors (1).

665629 is an equidigital number, since it uses as much as digits as its factorization.

665629 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19440, while the sum is 34.

The square root of 665629 is about 815.8608950060. The cubic root of 665629 is about 87.3126986711.

The spelling of 665629 in words is "six hundred sixty-five thousand, six hundred twenty-nine".