9991768247 has 4 divisors (see below), whose sum is σ = 9991969416. Its totient is φ = 9991567080.

The previous prime is 9991768243. The next prime is 9991768249. The reversal of 9991768247 is 7428671999.

9991768247 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 9991768247 - 2² = 9991768243 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 9991768247.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9991768243) 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 in 3 ways as a sum of consecutive naturals, for example, 33497 + ... + 145277.

It is an arithmetic number, because the mean of its divisors is an integer number (2497992354).

Almost surely, 2^9991768247 is an apocalyptic number.

9991768247 is a deficient number, since it is larger than the sum of its proper divisors (201169).

9991768247 is a wasteful number, since it uses less digits than its factorization.

9991768247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 201168.

The product of its digits is 13716864, while the sum is 62.

The square root of 9991768247 is about 99958.8327612923. The cubic root of 9991768247 is about 2153.8433686077.

The spelling of 9991768247 in words is "nine billion, nine hundred ninety-one million, seven hundred sixty-eight thousand, two hundred forty-seven".