9749991 has 4 divisors (see below), whose sum is σ = 12999992. Its totient is φ = 6499992.

The previous prime is 9749989. The next prime is 9750001. The reversal of 9749991 is 1999479.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1999479 = 3 ⋅666493.

It is not a de Polignac number, because 9749991 - 2¹ = 9749989 is a prime.

It is a Duffinian number.

9749991 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 9749991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9749911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1624996 + ... + 1625001.

It is an arithmetic number, because the mean of its divisors is an integer number (3249998).

Almost surely, 2^9749991 is an apocalyptic number.

9749991 is a deficient number, since it is larger than the sum of its proper divisors (3250001).

9749991 is a wasteful number, since it uses less digits than its factorization.

9749991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3250000.

The product of its digits is 183708, while the sum is 48.

The square root of 9749991 is about 3122.4975580455. The cubic root of 9749991 is about 213.6328683517.

The spelling of 9749991 in words is "nine million, seven hundred forty-nine thousand, nine hundred ninety-one".