8120991 has 16 divisors (see below), whose sum is σ = 11110400. Its totient is φ = 5274720.

The previous prime is 8120953. The next prime is 8121011. The reversal of 8120991 is 1990218.

8120991 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 8120991 - 2⁹ = 8120479 is a prime.

It is a Duffinian number.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8120921) 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 15 ways as a sum of consecutive naturals, for example, 36306 + ... + 36528.

It is an arithmetic number, because the mean of its divisors is an integer number (694400).

Almost surely, 2^8120991 is an apocalyptic number.

8120991 is a deficient number, since it is larger than the sum of its proper divisors (2989409).

8120991 is a wasteful number, since it uses less digits than its factorization.

8120991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 486.

The product of its (nonzero) digits is 1296, while the sum is 30.

The square root of 8120991 is about 2849.7352508610. The cubic root of 8120991 is about 201.0032176906.

The spelling of 8120991 in words is "eight million, one hundred twenty thousand, nine hundred ninety-one".