1656042406561 has 2 divisors, whose sum is σ = 1656042406562. Its totient is φ = 1656042406560.

The previous prime is 1656042406537. The next prime is 1656042406567.

1656042406561 is nontrivially palindromic in base 10.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 838204336225 + 817838070336 = 915535^2 + 904344^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 1656042406561 - 2³⁹ = 1106286592673 is a prime.

It is not a weakly prime, because it can be changed into another prime (1656042406567) 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 as a sum of consecutive naturals, namely, 828021203280 + 828021203281.

It is an arithmetic number, because the mean of its divisors is an integer number (828021203281).

Almost surely, 2^{1656042406561} is an apocalyptic number.

It is an amenable number.

1656042406561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1656042406561 is an equidigital number, since it uses as much as digits as its factorization.

1656042406561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1036800, while the sum is 46.

The spelling of 1656042406561 in words is "one trillion, six hundred fifty-six billion, forty-two million, four hundred six thousand, five hundred sixty-one".