689831 has 2 divisors, whose sum is σ = 689832. Its totient is φ = 689830.

The previous prime is 689827. The next prime is 689851. The reversal of 689831 is 138986.

689831 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 689831 - 2² = 689827 is a prime.

It is a super-2 number, since 2×689831² = 951733617122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 689791 and 689800.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (689851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344915 + 344916.

It is an arithmetic number, because the mean of its divisors is an integer number (344916).

2⁶⁸⁹⁸³¹ is an apocalyptic number.

689831 is a deficient number, since it is larger than the sum of its proper divisors (1).

689831 is an equidigital number, since it uses as much as digits as its factorization.

689831 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 35.

The square root of 689831 is about 830.5606540163. The cubic root of 689831 is about 88.3583442487.

The spelling of 689831 in words is "six hundred eighty-nine thousand, eight hundred thirty-one".