16527516521 has 4 divisors (see below), whose sum is σ = 16570004100. Its totient is φ = 16485028944.

The previous prime is 16527516461. The next prime is 16527516557. The reversal of 16527516521 is 12561572561.

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 2858399296 + 13669117225 = 53464^2 + 116915^2 .

It is a cyclic number.

It is not a de Polignac number, because 16527516521 - 2⁶ = 16527516457 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (16527516821) 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, 21243206 + ... + 21243983.

It is an arithmetic number, because the mean of its divisors is an integer number (4142501025).

Almost surely, 2^16527516521 is an apocalyptic number.

It is an amenable number.

16527516521 is a deficient number, since it is larger than the sum of its proper divisors (42487579).

16527516521 is an equidigital number, since it uses as much as digits as its factorization.

16527516521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42487578.

The product of its digits is 126000, while the sum is 41.

The spelling of 16527516521 in words is "sixteen billion, five hundred twenty-seven million, five hundred sixteen thousand, five hundred twenty-one".