853661816869 has 2 divisors, whose sum is σ = 853661816870. Its totient is φ = 853661816868.

The previous prime is 853661816797. The next prime is 853661816893. The reversal of 853661816869 is 968618166358.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 563194714369 + 290467102500 = 750463^2 + 538950^2 .

It is a cyclic number.

It is not a de Polignac number, because 853661816869 - 2³⁷ = 716222863397 is a prime.

It is a super-2 number, since 2×853661816869² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (853661811869) 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, 426830908434 + 426830908435.

It is an arithmetic number, because the mean of its divisors is an integer number (426830908435).

Almost surely, 2^853661816869 is an apocalyptic number.

It is an amenable number.

853661816869 is a deficient number, since it is larger than the sum of its proper divisors (1).

853661816869 is an equidigital number, since it uses as much as digits as its factorization.

853661816869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 89579520, while the sum is 67.

The spelling of 853661816869 in words is "eight hundred fifty-three billion, six hundred sixty-one million, eight hundred sixteen thousand, eight hundred sixty-nine".