821087 has 4 divisors (see below), whose sum is σ = 824736. Its totient is φ = 817440.

The previous prime is 821081. The next prime is 821089. The reversal of 821087 is 780128.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 821087 - 2¹⁴ = 804703 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 (821081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1463 + ... + 1944.

It is an arithmetic number, because the mean of its divisors is an integer number (206184).

2⁸²¹⁰⁸⁷ is an apocalyptic number.

821087 is a deficient number, since it is larger than the sum of its proper divisors (3649).

821087 is a wasteful number, since it uses less digits than its factorization.

821087 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3648.

The product of its (nonzero) digits is 896, while the sum is 26.

The square root of 821087 is about 906.1385103835. The cubic root of 821087 is about 93.6403565594.

The spelling of 821087 in words is "eight hundred twenty-one thousand, eighty-seven".