689257 has 2 divisors, whose sum is σ = 689258. Its totient is φ = 689256.

The previous prime is 689237. The next prime is 689261. The reversal of 689257 is 752986.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 670761 + 18496 = 819^2 + 136^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-689257 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (689237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344628 + 344629.

It is an arithmetic number, because the mean of its divisors is an integer number (344629).

2⁶⁸⁹²⁵⁷ is an apocalyptic number.

It is an amenable number.

689257 is a deficient number, since it is larger than the sum of its proper divisors (1).

689257 is an equidigital number, since it uses as much as digits as its factorization.

689257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30240, while the sum is 37.

The square root of 689257 is about 830.2150323862. The cubic root of 689257 is about 88.3338301463. Note that the first 3 decimals are identical.

It can be divided in two parts, 689 and 257, that added together give a triangular number (946 = T₄₃).

The spelling of 689257 in words is "six hundred eighty-nine thousand, two hundred fifty-seven".