528630021 has 6 divisors (see below), whose sum is σ = 763576710. Its totient is φ = 352420008.

The previous prime is 528630017. The next prime is 528630049. The reversal of 528630021 is 120036825.

528630021 is a `hidden beast` number, since 5 + 2 + 8 + 630 + 0 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 324540225 + 204089796 = 18015^2 + 14286^2 .

It is not a de Polignac number, because 528630021 - 2² = 528630017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (528630721) 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 in 5 ways as a sum of consecutive naturals, for example, 29368326 + ... + 29368343.

It is an arithmetic number, because the mean of its divisors is an integer number (127262785).

Almost surely, 2^528630021 is an apocalyptic number.

It is an amenable number.

528630021 is a deficient number, since it is larger than the sum of its proper divisors (234946689).

528630021 is a wasteful number, since it uses less digits than its factorization.

528630021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58736675 (or 58736672 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 528630021 is about 22991.9555714602. The cubic root of 528630021 is about 808.5693493361.

Adding to 528630021 its reverse (120036825), we get a palindrome (648666846).

The spelling of 528630021 in words is "five hundred twenty-eight million, six hundred thirty thousand, twenty-one".