531689 has 2 divisors, whose sum is σ = 531690. Its totient is φ = 531688.

The previous prime is 531673. The next prime is 531701. The reversal of 531689 is 986135.

Added to its reverse (986135) it gives a square (1517824 = 1232²).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 313600 + 218089 = 560^2 + 467^2 .

It is a cyclic number.

It is not a de Polignac number, because 531689 - 2⁴ = 531673 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (531589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 265844 + 265845.

It is an arithmetic number, because the mean of its divisors is an integer number (265845).

531689 is a Friedman number, since it can be written as 9^6+5+81*3, using all its digits and the basic arithmetic operations.

2⁵³¹⁶⁸⁹ is an apocalyptic number.

It is an amenable number.

531689 is a deficient number, since it is larger than the sum of its proper divisors (1).

531689 is an equidigital number, since it uses as much as digits as its factorization.

531689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6480, while the sum is 32.

The square root of 531689 is about 729.1700761825. The cubic root of 531689 is about 81.0125977459.

Adding to 531689 its reverse (986135), we get a square (1517824 = 1232²).

The spelling of 531689 in words is "five hundred thirty-one thousand, six hundred eighty-nine".