1636664354561 has 2 divisors, whose sum is σ = 1636664354562. Its totient is φ = 1636664354560.

The previous prime is 1636664354557. The next prime is 1636664354579. The reversal of 1636664354561 is 1654534666361.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1525148430961 + 111515923600 = 1234969^2 + 333940^2 .

It is a cyclic number.

It is not a de Polignac number, because 1636664354561 - 2² = 1636664354557 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1636664354497 and 1636664354506.

It is not a weakly prime, because it can be changed into another prime (1636661354561) 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, 818332177280 + 818332177281.

It is an arithmetic number, because the mean of its divisors is an integer number (818332177281).

Almost surely, 2^{1636664354561} is an apocalyptic number.

It is an amenable number.

1636664354561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1636664354561 is an equidigital number, since it uses as much as digits as its factorization.

1636664354561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27993600, while the sum is 56.

The spelling of 1636664354561 in words is "one trillion, six hundred thirty-six billion, six hundred sixty-four million, three hundred fifty-four thousand, five hundred sixty-one".