821321271 has 12 divisors (see below), whose sum is σ = 1200647448. Its totient is φ = 540950064.

The previous prime is 821321269. The next prime is 821321297. The reversal of 821321271 is 172123128.

It is not a de Polignac number, because 821321271 - 2¹ = 821321269 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821323271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 549000 + ... + 550493.

It is an arithmetic number, because the mean of its divisors is an integer number (100053954).

Almost surely, 2^821321271 is an apocalyptic number.

821321271 is a deficient number, since it is larger than the sum of its proper divisors (379326177).

821321271 is a wasteful number, since it uses less digits than its factorization.

821321271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1099582 (or 1099579 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 821321271 is about 28658.7032330495. The cubic root of 821321271 is about 936.4926147610.

Adding to 821321271 its reverse (172123128), we get a palindrome (993444399).

The spelling of 821321271 in words is "eight hundred twenty-one million, three hundred twenty-one thousand, two hundred seventy-one".