8531405916561 has 24 divisors (see below), whose sum is σ = 13471032154944. Its totient is φ = 5159931867360.

The previous prime is 8531405916541. The next prime is 8531405916563. The reversal of 8531405916561 is 1656195041358.

It is a happy number.

8531405916561 is a `hidden beast` number, since 8 + 5 + 3 + 1 + 40 + 591 + 6 + 5 + 6 + 1 = 666.

It is not a de Polignac number, because 8531405916561 - 2⁹ = 8531405916049 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 8531405916498 and 8531405916507.

It is not an unprimeable number, because it can be changed into a prime (8531405916563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 88427986 + ... + 88524411.

It is an arithmetic number, because the mean of its divisors is an integer number (561293006456).

Almost surely, 2^{8531405916561} is an apocalyptic number.

It is an amenable number.

8531405916561 is a deficient number, since it is larger than the sum of its proper divisors (4939626238383).

8531405916561 is a wasteful number, since it uses less digits than its factorization.

8531405916561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176952901 (or 176952898 counting only the distinct ones).

The product of its (nonzero) digits is 3888000, while the sum is 54.

The spelling of 8531405916561 in words is "eight trillion, five hundred thirty-one billion, four hundred five million, nine hundred sixteen thousand, five hundred sixty-one".