823147521 has 16 divisors (see below), whose sum is σ = 1279920000. Its totient is φ = 470369424.

The previous prime is 823147511. The next prime is 823147541. The reversal of 823147521 is 125741328.

It is not a de Polignac number, because 823147521 - 2⁹ = 823147009 is a prime.

It is not an unprimeable number, because it can be changed into a prime (823147511) 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, 398946 + ... + 401003.

It is an arithmetic number, because the mean of its divisors is an integer number (79995000).

Almost surely, 2^823147521 is an apocalyptic number.

It is an amenable number.

823147521 is a deficient number, since it is larger than the sum of its proper divisors (456772479).

823147521 is an equidigital number, since it uses as much as digits as its factorization.

823147521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 799973 (or 799959 counting only the distinct ones).

The product of its digits is 13440, while the sum is 33.

The square root of 823147521 is about 28690.5475897551. The cubic root of 823147521 is about 937.1862140616.

Adding to 823147521 its reverse (125741328), we get a palindrome (948888849).

The spelling of 823147521 in words is "eight hundred twenty-three million, one hundred forty-seven thousand, five hundred twenty-one".