821673 has 6 divisors (see below), whose sum is σ = 1186874. Its totient is φ = 547776.

The previous prime is 821663. The next prime is 821677. The reversal of 821673 is 376128.

It can be written as a sum of positive squares in only one way, i.e., 700569 + 121104 = 837^2 + 348^2 .

It is not a de Polignac number, because 821673 - 2⁵ = 821641 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (821677) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 45640 + ... + 45657.

2⁸²¹⁶⁷³ is an apocalyptic number.

It is an amenable number.

821673 is a deficient number, since it is larger than the sum of its proper divisors (365201).

821673 is a wasteful number, since it uses less digits than its factorization.

821673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91303 (or 91300 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 821673 is about 906.4618028356. The cubic root of 821673 is about 93.6626279306.

The spelling of 821673 in words is "eight hundred twenty-one thousand, six hundred seventy-three".