691289 has 2 divisors, whose sum is σ = 691290. Its totient is φ = 691288.

The previous prime is 691267. The next prime is 691297. The reversal of 691289 is 982196.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 648025 + 43264 = 805^2 + 208^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-691289 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (691189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345644 + 345645.

It is an arithmetic number, because the mean of its divisors is an integer number (345645).

2⁶⁹¹²⁸⁹ is an apocalyptic number.

It is an amenable number.

691289 is a deficient number, since it is larger than the sum of its proper divisors (1).

691289 is an equidigital number, since it uses as much as digits as its factorization.

691289 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 35.

The square root of 691289 is about 831.4379110914. The cubic root of 691289 is about 88.4205506981.

The spelling of 691289 in words is "six hundred ninety-one thousand, two hundred eighty-nine".