211356304145561 has 2 divisors, whose sum is σ = 211356304145562. Its totient is φ = 211356304145560.

The previous prime is 211356304145557. The next prime is 211356304145599. The reversal of 211356304145561 is 165541403653112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 211302389627536 + 53914518025 = 14536244^2 + 232195^2 .

It is a cyclic number.

It is not a de Polignac number, because 211356304145561 - 2² = 211356304145557 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (211356304145761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105678152072780 + 105678152072781.

It is an arithmetic number, because the mean of its divisors is an integer number (105678152072781).

Almost surely, 2^{211356304145561} is an apocalyptic number.

It is an amenable number.

211356304145561 is a deficient number, since it is larger than the sum of its proper divisors (1).

211356304145561 is an equidigital number, since it uses as much as digits as its factorization.

211356304145561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296000, while the sum is 47.

Adding to 211356304145561 its reverse (165541403653112), we get a palindrome (376897707798673).

The spelling of 211356304145561 in words is "two hundred eleven trillion, three hundred fifty-six billion, three hundred four million, one hundred forty-five thousand, five hundred sixty-one".