261972609089 has 2 divisors, whose sum is σ = 261972609090. Its totient is φ = 261972609088.

The previous prime is 261972609001. The next prime is 261972609103. The reversal of 261972609089 is 980906279162.

261972609089 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 189762170689 + 72210438400 = 435617^2 + 268720^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261972609089 is a prime.

It is not a weakly prime, because it can be changed into another prime (261972600089) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130986304544 + 130986304545.

It is an arithmetic number, because the mean of its divisors is an integer number (130986304545).

Almost surely, 2^261972609089 is an apocalyptic number.

It is an amenable number.

261972609089 is a deficient number, since it is larger than the sum of its proper divisors (1).

261972609089 is an equidigital number, since it uses as much as digits as its factorization.

261972609089 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5878656, while the sum is 59.

The spelling of 261972609089 in words is "two hundred sixty-one billion, nine hundred seventy-two million, six hundred nine thousand, eighty-nine".