690689 has 2 divisors, whose sum is σ = 690690. Its totient is φ = 690688.

The previous prime is 690673. The next prime is 690719. The reversal of 690689 is 986096.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 588289 + 102400 = 767^2 + 320^2 .

It is a cyclic number.

It is not a de Polignac number, because 690689 - 2⁴ = 690673 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (690629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345344 + 345345.

It is an arithmetic number, because the mean of its divisors is an integer number (345345).

2⁶⁹⁰⁶⁸⁹ is an apocalyptic number.

It is an amenable number.

690689 is a deficient number, since it is larger than the sum of its proper divisors (1).

690689 is an equidigital number, since it uses as much as digits as its factorization.

690689 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 38.

The square root of 690689 is about 831.0770120753. The cubic root of 690689 is about 88.3949619372.

The spelling of 690689 in words is "six hundred ninety thousand, six hundred eighty-nine".