659661 has 16 divisors (see below), whose sum is σ = 944640. Its totient is φ = 408240.

The previous prime is 659657. The next prime is 659669. The reversal of 659661 is 166956.

It is not a de Polignac number, because 659661 - 2² = 659657 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (659669) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3966 + ... + 4128.

It is an arithmetic number, because the mean of its divisors is an integer number (59040).

2⁶⁵⁹⁶⁶¹ is an apocalyptic number.

It is an amenable number.

659661 is a deficient number, since it is larger than the sum of its proper divisors (284979).

659661 is a wasteful number, since it uses less digits than its factorization.

659661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256.

The product of its digits is 9720, while the sum is 33.

The square root of 659661 is about 812.1951735882. The cubic root of 659661 is about 87.0509676253.

The spelling of 659661 in words is "six hundred fifty-nine thousand, six hundred sixty-one".