8138921 has 8 divisors (see below), whose sum is σ = 9387840. Its totient is φ = 6911568.

The previous prime is 8138909. The next prime is 8138947. The reversal of 8138921 is 1298318.

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

It is a cyclic number.

It is not a de Polignac number, because 8138921 - 2¹⁰ = 8137897 is a prime.

It is not an unprimeable number, because it can be changed into a prime (8138981) 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 7 ways as a sum of consecutive naturals, for example, 4571 + ... + 6096.

It is an arithmetic number, because the mean of its divisors is an integer number (1173480).

Almost surely, 2^8138921 is an apocalyptic number.

It is an amenable number.

8138921 is a deficient number, since it is larger than the sum of its proper divisors (1248919).

8138921 is a wasteful number, since it uses less digits than its factorization.

8138921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10783.

The product of its digits is 3456, while the sum is 32.

The square root of 8138921 is about 2852.8794226185. The cubic root of 8138921 is about 201.1510378510.

The spelling of 8138921 in words is "eight million, one hundred thirty-eight thousand, nine hundred twenty-one".