8921891 has 4 divisors (see below), whose sum is σ = 9732984. Its totient is φ = 8110800.

The previous prime is 8921873. The next prime is 8921911. The reversal of 8921891 is 1981298.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 8921891 - 2¹⁰ = 8920867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8921791) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 405530 + ... + 405551.

It is an arithmetic number, because the mean of its divisors is an integer number (2433246).

Almost surely, 2^8921891 is an apocalyptic number.

8921891 is a deficient number, since it is larger than the sum of its proper divisors (811093).

8921891 is a wasteful number, since it uses less digits than its factorization.

8921891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 811092.

The product of its digits is 10368, while the sum is 38.

The square root of 8921891 is about 2986.9534646526. The cubic root of 8921891 is about 207.4048801945.

The spelling of 8921891 in words is "eight million, nine hundred twenty-one thousand, eight hundred ninety-one".