16530624521 has 4 divisors (see below), whose sum is σ = 16563101700. Its totient is φ = 16498147344.

The previous prime is 16530624499. The next prime is 16530624557. The reversal of 16530624521 is 12542603561.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10818288121 + 5712336400 = 104011^2 + 75580^2 .

It is a cyclic number.

It is not a de Polignac number, because 16530624521 - 2¹⁸ = 16530362377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16530614521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16237826 + ... + 16238843.

It is an arithmetic number, because the mean of its divisors is an integer number (4140775425).

Almost surely, 2^16530624521 is an apocalyptic number.

It is an amenable number.

16530624521 is a deficient number, since it is larger than the sum of its proper divisors (32477179).

16530624521 is an equidigital number, since it uses as much as digits as its factorization.

16530624521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32477178.

The product of its (nonzero) digits is 43200, while the sum is 35.

The spelling of 16530624521 in words is "sixteen billion, five hundred thirty million, six hundred twenty-four thousand, five hundred twenty-one".