2106537436561 has 2 divisors, whose sum is σ = 2106537436562. Its totient is φ = 2106537436560.

The previous prime is 2106537436559. The next prime is 2106537436567. The reversal of 2106537436561 is 1656347356012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1921775010961 + 184762425600 = 1386281^2 + 429840^2 .

It is a cyclic number.

It is not a de Polignac number, because 2106537436561 - 2¹ = 2106537436559 is a prime.

Together with 2106537436559, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (2106537436567) 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 as a sum of consecutive naturals, namely, 1053268718280 + 1053268718281.

It is an arithmetic number, because the mean of its divisors is an integer number (1053268718281).

Almost surely, 2^{2106537436561} is an apocalyptic number.

It is an amenable number.

2106537436561 is a deficient number, since it is larger than the sum of its proper divisors (1).

2106537436561 is an equidigital number, since it uses as much as digits as its factorization.

2106537436561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2721600, while the sum is 49.

The spelling of 2106537436561 in words is "two trillion, one hundred six billion, five hundred thirty-seven million, four hundred thirty-six thousand, five hundred sixty-one".