689951 has 2 divisors, whose sum is σ = 689952. Its totient is φ = 689950.

The previous prime is 689929. The next prime is 689957. The reversal of 689951 is 159986.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 689951 - 2¹⁴ = 673567 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (689957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344975 + 344976.

It is an arithmetic number, because the mean of its divisors is an integer number (344976).

2⁶⁸⁹⁹⁵¹ is an apocalyptic number.

689951 is a deficient number, since it is larger than the sum of its proper divisors (1).

689951 is an equidigital number, since it uses as much as digits as its factorization.

689951 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19440, while the sum is 38.

The square root of 689951 is about 830.6328912341. The cubic root of 689951 is about 88.3634674294.

The spelling of 689951 in words is "six hundred eighty-nine thousand, nine hundred fifty-one".