821853 has 16 divisors (see below), whose sum is σ = 1240000. Its totient is φ = 537840.

The previous prime is 821851. The next prime is 821857. The reversal of 821853 is 358128.

It is a happy number.

821853 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 821853 - 2¹ = 821851 is a prime.

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

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821851) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1398 + ... + 1896.

It is an arithmetic number, because the mean of its divisors is an integer number (77500).

2⁸²¹⁸⁵³ is an apocalyptic number.

It is an amenable number.

821853 is a deficient number, since it is larger than the sum of its proper divisors (418147).

821853 is a wasteful number, since it uses less digits than its factorization.

821853 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 569 (or 563 counting only the distinct ones).

The product of its digits is 1920, while the sum is 27.

The square root of 821853 is about 906.5610845387. The cubic root of 821853 is about 93.6694668402.

The spelling of 821853 in words is "eight hundred twenty-one thousand, eight hundred fifty-three".