821128503 has 32 divisors (see below), whose sum is σ = 1202478592. Its totient is φ = 495331200.

The previous prime is 821128489. The next prime is 821128513. The reversal of 821128503 is 305821128.

It is not a de Polignac number, because 821128503 - 2¹² = 821124407 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 (821128513) 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 31 ways as a sum of consecutive naturals, for example, 1300998 + ... + 1301628.

It is an arithmetic number, because the mean of its divisors is an integer number (37577456).

Almost surely, 2^821128503 is an apocalyptic number.

821128503 is a deficient number, since it is larger than the sum of its proper divisors (381350089).

821128503 is a wasteful number, since it uses less digits than its factorization.

821128503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1255.

The product of its (nonzero) digits is 3840, while the sum is 30.

The square root of 821128503 is about 28655.3398688621. The cubic root of 821128503 is about 936.4193426080.

The spelling of 821128503 in words is "eight hundred twenty-one million, one hundred twenty-eight thousand, five hundred three".