7857528561 has 6 divisors (see below), whose sum is σ = 11349763490. Its totient is φ = 5238352368.

The previous prime is 7857528541. The next prime is 7857528619. The reversal of 7857528561 is 1658257587.

7857528561 is a `hidden beast` number, since 7 + 8 + 5 + 75 + 2 + 8 + 561 = 666.

It can be written as a sum of positive squares in only one way, i.e., 4876368561 + 2981160000 = 69831^2 + 54600^2 .

It is not a de Polignac number, because 7857528561 - 2⁵ = 7857528529 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 7857528498 and 7857528507.

It is not an unprimeable number, because it can be changed into a prime (7857528541) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 436529356 + ... + 436529373.

Almost surely, 2^7857528561 is an apocalyptic number.

It is an amenable number.

7857528561 is a deficient number, since it is larger than the sum of its proper divisors (3492234929).

7857528561 is a wasteful number, since it uses less digits than its factorization.

7857528561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 873058735 (or 873058732 counting only the distinct ones).

The product of its digits is 4704000, while the sum is 54.

The square root of 7857528561 is about 88642.7016792697. The cubic root of 7857528561 is about 1988.0561948288.

The spelling of 7857528561 in words is "seven billion, eight hundred fifty-seven million, five hundred twenty-eight thousand, five hundred sixty-one".