821047 has 8 divisors (see below), whose sum is σ = 876800. Its totient is φ = 766584.

The previous prime is 821039. The next prime is 821053. The reversal of 821047 is 740128.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 821047 - 2³ = 821039 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 (821027) 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 7 ways as a sum of consecutive naturals, for example, 1228 + ... + 1774.

It is an arithmetic number, because the mean of its divisors is an integer number (109600).

2⁸²¹⁰⁴⁷ is an apocalyptic number.

821047 is a deficient number, since it is larger than the sum of its proper divisors (55753).

821047 is a wasteful number, since it uses less digits than its factorization.

821047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 645.

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 821047 is about 906.1164384338. The cubic root of 821047 is about 93.6388359430.

The spelling of 821047 in words is "eight hundred twenty-one thousand, forty-seven".