71206525661 has 2 divisors, whose sum is σ = 71206525662. Its totient is φ = 71206525660.

The previous prime is 71206525633. The next prime is 71206525681. The reversal of 71206525661 is 16652560217.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63601813636 + 7604712025 = 252194^2 + 87205^2 .

It is a cyclic number.

It is not a de Polignac number, because 71206525661 - 2¹⁴ = 71206509277 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71206525681) 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, 35603262830 + 35603262831.

It is an arithmetic number, because the mean of its divisors is an integer number (35603262831).

Almost surely, 2^71206525661 is an apocalyptic number.

It is an amenable number.

71206525661 is a deficient number, since it is larger than the sum of its proper divisors (1).

71206525661 is an equidigital number, since it uses as much as digits as its factorization.

71206525661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 151200, while the sum is 41.

The spelling of 71206525661 in words is "seventy-one billion, two hundred six million, five hundred twenty-five thousand, six hundred sixty-one".