8129891 has 16 divisors (see below), whose sum is σ = 10671360. Its totient is φ = 6000480.

The previous prime is 8129873. The next prime is 8129903. The reversal of 8129891 is 1989218.

It is a cyclic number.

It is not a de Polignac number, because 8129891 - 2¹⁸ = 7867747 is a prime.

It is not an unprimeable number, because it can be changed into a prime (8129801) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1316 + ... + 4241.

It is an arithmetic number, because the mean of its divisors is an integer number (666960).

Almost surely, 2^8129891 is an apocalyptic number.

8129891 is a deficient number, since it is larger than the sum of its proper divisors (2541469).

8129891 is a wasteful number, since it uses less digits than its factorization.

8129891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5594.

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

The square root of 8129891 is about 2851.2963718281. The cubic root of 8129891 is about 201.0766190577.

The spelling of 8129891 in words is "eight million, one hundred twenty-nine thousand, eight hundred ninety-one".