660817 has 2 divisors, whose sum is σ = 660818. Its totient is φ = 660816.

The previous prime is 660811. The next prime is 660833. The reversal of 660817 is 718066.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 389376 + 271441 = 624^2 + 521^2 .

It is a cyclic number.

It is not a de Polignac number, because 660817 - 2³ = 660809 is a prime.

It is a super-3 number, since 3×660817³ = 865694933320675539, which contains 333 as substring.

660817 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (660811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330408 + 330409.

It is an arithmetic number, because the mean of its divisors is an integer number (330409).

2⁶⁶⁰⁸¹⁷ is an apocalyptic number.

It is an amenable number.

660817 is a deficient number, since it is larger than the sum of its proper divisors (1).

660817 is an equidigital number, since it uses as much as digits as its factorization.

660817 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 660817 is about 812.9065136902. The cubic root of 660817 is about 87.1017877654.

The spelling of 660817 in words is "six hundred sixty thousand, eight hundred seventeen".