9921492791 has 8 divisors (see below), whose sum is σ = 12005840160. Its totient is φ = 8003893248.

The previous prime is 9921492671. The next prime is 9921492793. The reversal of 9921492791 is 1972941299.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9921492791 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 (9921492793) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41686826 + ... + 41687063.

It is an arithmetic number, because the mean of its divisors is an integer number (1500730020).

Almost surely, 2^9921492791 is an apocalyptic number.

9921492791 is a deficient number, since it is larger than the sum of its proper divisors (2084347369).

9921492791 is a wasteful number, since it uses less digits than its factorization.

9921492791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83373913.

The product of its digits is 734832, while the sum is 53.

The square root of 9921492791 is about 99606.6904931591. The cubic root of 9921492791 is about 2148.7819161897.

The spelling of 9921492791 in words is "nine billion, nine hundred twenty-one million, four hundred ninety-two thousand, seven hundred ninety-one".