8991389 has 12 divisors (see below), whose sum is σ = 10405920. Its totient is φ = 7741800.

The previous prime is 8991383. The next prime is 8991401. The reversal of 8991389 is 9831998.

It is not a de Polignac number, because 8991389 - 2¹⁶ = 8925853 is a prime.

It is a super-2 number, since 2×8991389² = 161690152298642, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8991383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 344 + ... + 4254.

It is an arithmetic number, because the mean of its divisors is an integer number (867160).

Almost surely, 2^8991389 is an apocalyptic number.

It is an amenable number.

8991389 is a deficient number, since it is larger than the sum of its proper divisors (1414531).

8991389 is a wasteful number, since it uses less digits than its factorization.

8991389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3952 (or 3941 counting only the distinct ones).

The product of its digits is 139968, while the sum is 47.

The square root of 8991389 is about 2998.5644898851. The cubic root of 8991389 is about 207.9420218707.

The spelling of 8991389 in words is "eight million, nine hundred ninety-one thousand, three hundred eighty-nine".