687923 has 2 divisors, whose sum is σ = 687924. Its totient is φ = 687922.

The previous prime is 687917. The next prime is 687931. The reversal of 687923 is 329786.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 687923 - 2¹⁸ = 425779 is a prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (687023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343961 + 343962.

It is an arithmetic number, because the mean of its divisors is an integer number (343962).

2⁶⁸⁷⁹²³ is an apocalyptic number.

687923 is a deficient number, since it is larger than the sum of its proper divisors (1).

687923 is an equidigital number, since it uses as much as digits as its factorization.

687923 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18144, while the sum is 35.

The square root of 687923 is about 829.4112369627. The cubic root of 687923 is about 88.2768057308.

The spelling of 687923 in words is "six hundred eighty-seven thousand, nine hundred twenty-three".