820287 has 40 divisors (see below), whose sum is σ = 1422960. Its totient is φ = 466560.

The previous prime is 820279. The next prime is 820319. The reversal of 820287 is 782028.

820287 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 820287 - 2³ = 820279 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 820287.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 820287.

It is not an unprimeable number, because it can be changed into a prime (820247) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 19987 + ... + 20027.

It is an arithmetic number, because the mean of its divisors is an integer number (35574).

2⁸²⁰²⁸⁷ is an apocalyptic number.

820287 is a deficient number, since it is larger than the sum of its proper divisors (602673).

820287 is a wasteful number, since it uses less digits than its factorization.

820287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85 (or 76 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The square root of 820287 is about 905.6969691900. The cubic root of 820287 is about 93.6099348429.

820287 divided by its sum of digits (27) gives a triangular number (30381 = T₂₄₆).

The spelling of 820287 in words is "eight hundred twenty thousand, two hundred eighty-seven".