61581896609 has 2 divisors, whose sum is σ = 61581896610. Its totient is φ = 61581896608.

The previous prime is 61581896603. The next prime is 61581896611. The reversal of 61581896609 is 90669818516.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51426900625 + 10154995984 = 226775^2 + 100772^2 .

It is a cyclic number.

It is not a de Polignac number, because 61581896609 - 2⁸ = 61581896353 is a prime.

Together with 61581896611, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (61581896603) 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, 30790948304 + 30790948305.

It is an arithmetic number, because the mean of its divisors is an integer number (30790948305).

Almost surely, 2^61581896609 is an apocalyptic number.

It is an amenable number.

61581896609 is a deficient number, since it is larger than the sum of its proper divisors (1).

61581896609 is an equidigital number, since it uses as much as digits as its factorization.

61581896609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5598720, while the sum is 59.

The spelling of 61581896609 in words is "sixty-one billion, five hundred eighty-one million, eight hundred ninety-six thousand, six hundred nine".