676821 has 16 divisors (see below), whose sum is σ = 998784. Its totient is φ = 405504.

The previous prime is 676807. The next prime is 676829. The reversal of 676821 is 128676.

It is a happy number.

It is not a de Polignac number, because 676821 - 2¹⁰ = 675797 is a prime.

676821 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (676829) 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 in 15 ways as a sum of consecutive naturals, for example, 885 + ... + 1461.

It is an arithmetic number, because the mean of its divisors is an integer number (62424).

2⁶⁷⁶⁸²¹ is an apocalyptic number.

It is an amenable number.

676821 is a deficient number, since it is larger than the sum of its proper divisors (321963).

676821 is a wasteful number, since it uses less digits than its factorization.

676821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 620.

The product of its digits is 4032, while the sum is 30.

The square root of 676821 is about 822.6913151359. The cubic root of 676821 is about 87.7993448166.

The spelling of 676821 in words is "six hundred seventy-six thousand, eight hundred twenty-one".