1656540456561 has 32 divisors (see below), whose sum is σ = 2672378256000. Its totient is φ = 1010158962624.

The previous prime is 1656540456367. The next prime is 1656540456647.

1656540456561 is a `hidden beast` number, since 1 + 6 + 5 + 6 + 540 + 45 + 6 + 56 + 1 = 666.

1656540456561 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1656540456561 - 2¹⁵ = 1656540423793 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1656540456498 and 1656540456507.

It is not an unprimeable number, because it can be changed into a prime (1656540458561) 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 31 ways as a sum of consecutive naturals, for example, 55659670 + ... + 55689423.

It is an arithmetic number, because the mean of its divisors is an integer number (83511820500).

Almost surely, 2^{1656540456561} is an apocalyptic number.

It is an amenable number.

1656540456561 is a deficient number, since it is larger than the sum of its proper divisors (1015837799439).

1656540456561 is a wasteful number, since it uses less digits than its factorization.

1656540456561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111349150 (or 111349144 counting only the distinct ones).

The product of its (nonzero) digits is 12960000, while the sum is 54.

The spelling of 1656540456561 in words is "one trillion, six hundred fifty-six billion, five hundred forty million, four hundred fifty-six thousand, five hundred sixty-one".