205489152646889 has 4 divisors (see below), whose sum is σ = 205489183756500. Its totient is φ = 205489121537280.

The previous prime is 205489152646871. The next prime is 205489152646901. The reversal of 205489152646889 is 988646251984502.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 34967211502864 + 170521941144025 = 5913308^2 + 13058405^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-205489152646889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205489152646819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1280264 + ... + 20312985.

It is an arithmetic number, because the mean of its divisors is an integer number (51372295939125).

Almost surely, 2^{205489152646889} is an apocalyptic number.

It is an amenable number.

205489152646889 is a deficient number, since it is larger than the sum of its proper divisors (31109611).

205489152646889 is an equidigital number, since it uses as much as digits as its factorization.

205489152646889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31109610.

The product of its (nonzero) digits is 2388787200, while the sum is 77.

The spelling of 205489152646889 in words is "two hundred five trillion, four hundred eighty-nine billion, one hundred fifty-two million, six hundred forty-six thousand, eight hundred eighty-nine".