821143 has 2 divisors, whose sum is σ = 821144. Its totient is φ = 821142.

The previous prime is 821131. The next prime is 821147. The reversal of 821143 is 341128.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-821143 is a prime.

821143 is a lucky number.

It is a plaindrome in base 13 and base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 821143.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (821147) 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 as a sum of consecutive naturals, namely, 410571 + 410572.

It is an arithmetic number, because the mean of its divisors is an integer number (410572).

2⁸²¹¹⁴³ is an apocalyptic number.

821143 is a deficient number, since it is larger than the sum of its proper divisors (1).

821143 is an equidigital number, since it uses as much as digits as its factorization.

821143 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 192, while the sum is 19.

The square root of 821143 is about 906.1694102098. The cubic root of 821143 is about 93.6424853394.

It can be divided in two parts, 82 and 1143, that added together give a triangular number (1225 = T₄₉).

The spelling of 821143 in words is "eight hundred twenty-one thousand, one hundred forty-three".