824020021 has 12 divisors (see below), whose sum is σ = 928876032. Its totient is φ = 724935000.

The previous prime is 824020013. The next prime is 824020049. The reversal of 824020021 is 120020428.

It is not a de Polignac number, because 824020021 - 2³ = 824020013 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 (824021021) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28405 + ... + 49546.

It is an arithmetic number, because the mean of its divisors is an integer number (77406336).

Almost surely, 2^824020021 is an apocalyptic number.

It is an amenable number.

824020021 is a deficient number, since it is larger than the sum of its proper divisors (104856011).

824020021 is a wasteful number, since it uses less digits than its factorization.

824020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78024 (or 77993 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 824020021 is about 28705.7489189883. The cubic root of 824020021 is about 937.5172224629.

Adding to 824020021 its reverse (120020428), we get a palindrome (944040449).

The spelling of 824020021 in words is "eight hundred twenty-four million, twenty thousand, twenty-one".