9661958343899 has 2 divisors, whose sum is σ = 9661958343900. Its totient is φ = 9661958343898.

The previous prime is 9661958343881. The next prime is 9661958343929. The reversal of 9661958343899 is 9983438591669.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 9661958343899 - 2¹⁶ = 9661958278363 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (9661958343839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4830979171949 + 4830979171950.

It is an arithmetic number, because the mean of its divisors is an integer number (4830979171950).

Almost surely, 2^{9661958343899} is an apocalyptic number.

9661958343899 is a deficient number, since it is larger than the sum of its proper divisors (1).

9661958343899 is an equidigital number, since it uses as much as digits as its factorization.

9661958343899 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2720977920, while the sum is 80.

The spelling of 9661958343899 in words is "nine trillion, six hundred sixty-one billion, nine hundred fifty-eight million, three hundred forty-three thousand, eight hundred ninety-nine".