8507528721 has 6 divisors (see below), whose sum is σ = 12288652610. Its totient is φ = 5671685808.

The previous prime is 8507528713. The next prime is 8507528753. The reversal of 8507528721 is 1278257058.

8507528721 is a `hidden beast` number, since 8 + 50 + 7 + 528 + 72 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 7458740496 + 1048788225 = 86364^2 + 32385^2 .

It is not a de Polignac number, because 8507528721 - 2³ = 8507528713 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 (8507528621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 472640476 + ... + 472640493.

Almost surely, 2^8507528721 is an apocalyptic number.

It is an amenable number.

8507528721 is a deficient number, since it is larger than the sum of its proper divisors (3781123889).

8507528721 is a wasteful number, since it uses less digits than its factorization.

8507528721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 945280975 (or 945280972 counting only the distinct ones).

The product of its (nonzero) digits is 313600, while the sum is 45.

The square root of 8507528721 is about 92236.2657581062. The cubic root of 8507528721 is about 2041.4299151587.

The spelling of 8507528721 in words is "eight billion, five hundred seven million, five hundred twenty-eight thousand, seven hundred twenty-one".