61660769809 has 2 divisors, whose sum is σ = 61660769810. Its totient is φ = 61660769808.

The previous prime is 61660769747. The next prime is 61660769861. The reversal of 61660769809 is 90896706616.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31618174225 + 30042595584 = 177815^2 + 173328^2 .

It is a cyclic number.

It is not a de Polignac number, because 61660769809 - 2¹¹ = 61660767761 is a prime.

It is not a weakly prime, because it can be changed into another prime (61660769869) 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, 30830384904 + 30830384905.

It is an arithmetic number, because the mean of its divisors is an integer number (30830384905).

Almost surely, 2^61660769809 is an apocalyptic number.

It is an amenable number.

61660769809 is a deficient number, since it is larger than the sum of its proper divisors (1).

61660769809 is an equidigital number, since it uses as much as digits as its factorization.

61660769809 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 58.

The spelling of 61660769809 in words is "sixty-one billion, six hundred sixty million, seven hundred sixty-nine thousand, eight hundred nine".