9941985709 has 2 divisors, whose sum is σ = 9941985710. Its totient is φ = 9941985708.

The previous prime is 9941985689. The next prime is 9941985719. The reversal of 9941985709 is 9075891499.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6403520484 + 3538465225 = 80022^2 + 59485^2 .

It is a cyclic number.

It is not a de Polignac number, because 9941985709 - 2¹⁵ = 9941952941 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9941985719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4970992854 + 4970992855.

It is an arithmetic number, because the mean of its divisors is an integer number (4970992855).

Almost surely, 2^9941985709 is an apocalyptic number.

It is an amenable number.

9941985709 is a deficient number, since it is larger than the sum of its proper divisors (1).

9941985709 is an equidigital number, since it uses as much as digits as its factorization.

9941985709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7348320, while the sum is 61.

The square root of 9941985709 is about 99709.5066129604. The cubic root of 9941985709 is about 2150.2603404954.

The spelling of 9941985709 in words is "nine billion, nine hundred forty-one million, nine hundred eighty-five thousand, seven hundred nine".