821007 has 12 divisors (see below), whose sum is σ = 1293864. Its totient is φ = 497520.

The previous prime is 821003. The next prime is 821027. The reversal of 821007 is 700128.

821007 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 821007 - 2² = 821003 is a prime.

821007 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821003) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4048 + ... + 4245.

It is an arithmetic number, because the mean of its divisors is an integer number (107822).

2⁸²¹⁰⁰⁷ is an apocalyptic number.

821007 is a deficient number, since it is larger than the sum of its proper divisors (472857).

821007 is a wasteful number, since it uses less digits than its factorization.

821007 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8310 (or 8307 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 18.

The square root of 821007 is about 906.0943659465. The cubic root of 821007 is about 93.6373152772.

It can be divided in two parts, 82 and 1007, that added together give a square (1089 = 33²).

The spelling of 821007 in words is "eight hundred twenty-one thousand, seven".