211944604657 has 2 divisors, whose sum is σ = 211944604658. Its totient is φ = 211944604656.

The previous prime is 211944604643. The next prime is 211944604687. The reversal of 211944604657 is 756406449112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 190996094961 + 20948509696 = 437031^2 + 144736^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211944604657 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 211944604657.

It is not a weakly prime, because it can be changed into another prime (211944604687) 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, 105972302328 + 105972302329.

It is an arithmetic number, because the mean of its divisors is an integer number (105972302329).

Almost surely, 2^211944604657 is an apocalyptic number.

It is an amenable number.

211944604657 is a deficient number, since it is larger than the sum of its proper divisors (1).

211944604657 is an equidigital number, since it uses as much as digits as its factorization.

211944604657 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1451520, while the sum is 49.

The spelling of 211944604657 in words is "two hundred eleven billion, nine hundred forty-four million, six hundred four thousand, six hundred fifty-seven".