9939691243 has 2 divisors, whose sum is σ = 9939691244. Its totient is φ = 9939691242.

The previous prime is 9939691193. The next prime is 9939691249. The reversal of 9939691243 is 3421969399.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 9939691243 - 2¹³ = 9939683051 is a prime.

It is not a weakly prime, because it can be changed into another prime (9939691249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4969845621 + 4969845622.

It is an arithmetic number, because the mean of its divisors is an integer number (4969845622).

Almost surely, 2^9939691243 is an apocalyptic number.

9939691243 is a deficient number, since it is larger than the sum of its proper divisors (1).

9939691243 is an equidigital number, since it uses as much as digits as its factorization.

9939691243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2834352, while the sum is 55.

The square root of 9939691243 is about 99698.0001955907. Note that the first 3 decimals coincide. The cubic root of 9939691243 is about 2150.0949114762.

The spelling of 9939691243 in words is "nine billion, nine hundred thirty-nine million, six hundred ninety-one thousand, two hundred forty-three".