687799 has 4 divisors (see below), whose sum is σ = 786064. Its totient is φ = 589536.

The previous prime is 687787. The next prime is 687809. The reversal of 687799 is 997786.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 687799 - 2⁵ = 687767 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687749) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49122 + ... + 49135.

It is an arithmetic number, because the mean of its divisors is an integer number (196516).

2⁶⁸⁷⁷⁹⁹ is an apocalyptic number.

687799 is a deficient number, since it is larger than the sum of its proper divisors (98265).

687799 is an equidigital number, since it uses as much as digits as its factorization.

687799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98264.

The product of its digits is 190512, while the sum is 46.

The square root of 687799 is about 829.3364817732. The cubic root of 687799 is about 88.2715013669.

The spelling of 687799 in words is "six hundred eighty-seven thousand, seven hundred ninety-nine".