820667 has 8 divisors (see below), whose sum is σ = 883200. Its totient is φ = 760104.

The previous prime is 820657. The next prime is 820679. The reversal of 820667 is 766028.

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 820667 - 2⁸ = 820411 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 7.

It is not an unprimeable number, because it can be changed into a prime (820627) 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, 434 + ... + 1352.

It is an arithmetic number, because the mean of its divisors is an integer number (110400).

2⁸²⁰⁶⁶⁷ is an apocalyptic number.

820667 is a deficient number, since it is larger than the sum of its proper divisors (62533).

820667 is a wasteful number, since it uses less digits than its factorization.

820667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 985.

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 820667 is about 905.9067280907. The cubic root of 820667 is about 93.6243876233.

The spelling of 820667 in words is "eight hundred twenty thousand, six hundred sixty-seven".