9774949991 has 4 divisors (see below), whose sum is σ = 9775351992. Its totient is φ = 9774547992.

The previous prime is 9774949979. The next prime is 9774949997. The reversal of 9774949991 is 1999494779.

It is a happy number.

9774949991 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, and also an emirpimes, since its reverse is a distinct semiprime: 1999494779 = 383 ⋅5220613.

It is a cyclic number.

It is not a de Polignac number, because 9774949991 - 2⁶ = 9774949927 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9774949997) 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, 162005 + ... + 213998.

It is an arithmetic number, because the mean of its divisors is an integer number (2443837998).

Almost surely, 2^9774949991 is an apocalyptic number.

9774949991 is a deficient number, since it is larger than the sum of its proper divisors (402001).

9774949991 is a wasteful number, since it uses less digits than its factorization.

9774949991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 402000.

The product of its digits is 46294416, while the sum is 68.

The square root of 9774949991 is about 98868.3467597188. The cubic root of 9774949991 is about 2138.1500586860.

The spelling of 9774949991 in words is "nine billion, seven hundred seventy-four million, nine hundred forty-nine thousand, nine hundred ninety-one".