690869 has 2 divisors, whose sum is σ = 690870. Its totient is φ = 690868.

The previous prime is 690841. The next prime is 690871. The reversal of 690869 is 968096.

690869 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 592900 + 97969 = 770^2 + 313^2 .

It is a cyclic number.

It is not a de Polignac number, because 690869 - 2¹² = 686773 is a prime.

It is a super-2 number, since 2×690869² = 954599950322, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 690871, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (690839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345434 + 345435.

It is an arithmetic number, because the mean of its divisors is an integer number (345435).

2⁶⁹⁰⁸⁶⁹ is an apocalyptic number.

It is an amenable number.

690869 is a deficient number, since it is larger than the sum of its proper divisors (1).

690869 is an equidigital number, since it uses as much as digits as its factorization.

690869 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 690869 is about 831.1852982338. The cubic root of 690869 is about 88.4026401210.

The spelling of 690869 in words is "six hundred ninety thousand, eight hundred sixty-nine".