659891 has 4 divisors (see below), whose sum is σ = 666792. Its totient is φ = 652992.

The previous prime is 659881. The next prime is 659899. The reversal of 659891 is 198956.

659891 = T₄₆₆ + T₄₆₇ + ... + T₄₇₁.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 659891 - 2¹⁴ = 643507 is a prime.

It is a super-2 number, since 2×659891² = 870912263762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (659899) 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, 3305 + ... + 3498.

It is an arithmetic number, because the mean of its divisors is an integer number (166698).

2⁶⁵⁹⁸⁹¹ is an apocalyptic number.

659891 is a deficient number, since it is larger than the sum of its proper divisors (6901).

659891 is an equidigital number, since it uses as much as digits as its factorization.

659891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6900.

The product of its digits is 19440, while the sum is 38.

The square root of 659891 is about 812.3367528310. The cubic root of 659891 is about 87.0610836274.

The spelling of 659891 in words is "six hundred fifty-nine thousand, eight hundred ninety-one".