8921391 has 8 divisors (see below), whose sum is σ = 12046080. Its totient is φ = 5872152.

The previous prime is 8921389. The next prime is 8921417. The reversal of 8921391 is 1931298.

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

It is not a de Polignac number, because 8921391 - 2¹ = 8921389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8921321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18585 + ... + 19058.

It is an arithmetic number, because the mean of its divisors is an integer number (1505760).

Almost surely, 2^8921391 is an apocalyptic number.

8921391 is a deficient number, since it is larger than the sum of its proper divisors (3124689).

8921391 is a wasteful number, since it uses less digits than its factorization.

8921391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37725.

The product of its digits is 3888, while the sum is 33.

The square root of 8921391 is about 2986.8697661599. The cubic root of 8921391 is about 207.4010056654.

The spelling of 8921391 in words is "eight million, nine hundred twenty-one thousand, three hundred ninety-one".