686993 has 2 divisors, whose sum is σ = 686994. Its totient is φ = 686992.

The previous prime is 686989. The next prime is 687007. The reversal of 686993 is 399686.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 620944 + 66049 = 788^2 + 257^2 .

It is a cyclic number.

It is not a de Polignac number, because 686993 - 2² = 686989 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 686993.

It is not a weakly prime, because it can be changed into another prime (686963) 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, 343496 + 343497.

It is an arithmetic number, because the mean of its divisors is an integer number (343497).

2⁶⁸⁶⁹⁹³ is an apocalyptic number.

It is an amenable number.

686993 is a deficient number, since it is larger than the sum of its proper divisors (1).

686993 is an equidigital number, since it uses as much as digits as its factorization.

686993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 69984, while the sum is 41.

The square root of 686993 is about 828.8504086987. The cubic root of 686993 is about 88.2370074526.

The spelling of 686993 in words is "six hundred eighty-six thousand, nine hundred ninety-three".