211517685653 has 2 divisors, whose sum is σ = 211517685654. Its totient is φ = 211517685652.

The previous prime is 211517685629. The next prime is 211517685713. The reversal of 211517685653 is 356586715112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 154686463204 + 56831222449 = 393302^2 + 238393^2 .

It is a cyclic number.

It is not a de Polignac number, because 211517685653 - 2⁸ = 211517685397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211517685053) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105758842826 + 105758842827.

It is an arithmetic number, because the mean of its divisors is an integer number (105758842827).

Almost surely, 2^211517685653 is an apocalyptic number.

It is an amenable number.

211517685653 is a deficient number, since it is larger than the sum of its proper divisors (1).

211517685653 is an equidigital number, since it uses as much as digits as its factorization.

211517685653 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1512000, while the sum is 50.

The spelling of 211517685653 in words is "two hundred eleven billion, five hundred seventeen million, six hundred eighty-five thousand, six hundred fifty-three".