688999 has 2 divisors, whose sum is σ = 689000. Its totient is φ = 688998.

The previous prime is 688979. The next prime is 689021. The reversal of 688999 is 999886.

688999 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 688999 - 2⁷ = 688871 is a prime.

688999 is a modest number, since divided by 999 gives 688 as remainder.

688999 is a lucky number.

It is a plaindrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (688939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344499 + 344500.

It is an arithmetic number, because the mean of its divisors is an integer number (344500).

2⁶⁸⁸⁹⁹⁹ is an apocalyptic number.

688999 is a deficient number, since it is larger than the sum of its proper divisors (1).

688999 is an equidigital number, since it uses as much as digits as its factorization.

688999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 279936, while the sum is 49.

The square root of 688999 is about 830.0596364117. The cubic root of 688999 is about 88.3228071789.

The spelling of 688999 in words is "six hundred eighty-eight thousand, nine hundred ninety-nine".