8921297991 has 8 divisors (see below), whose sum is σ = 11902700160. Its totient is φ = 5943713912.

The previous prime is 8921297933. The next prime is 8921297993. The reversal of 8921297991 is 1997921298.

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

It is a cyclic number.

It is not a de Polignac number, because 8921297991 - 2⁷ = 8921297863 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8921297993) 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 7 ways as a sum of consecutive naturals, for example, 949065 + ... + 958418.

It is an arithmetic number, because the mean of its divisors is an integer number (1487837520).

Almost surely, 2^8921297991 is an apocalyptic number.

8921297991 is a deficient number, since it is larger than the sum of its proper divisors (2981402169).

8921297991 is a wasteful number, since it uses less digits than its factorization.

8921297991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1909045.

The product of its digits is 1469664, while the sum is 57.

The square root of 8921297991 is about 94452.6229969290. The cubic root of 8921297991 is about 2074.0028491731.

The spelling of 8921297991 in words is "eight billion, nine hundred twenty-one million, two hundred ninety-seven thousand, nine hundred ninety-one".