8421121 has 4 divisors (see below), whose sum is σ = 8469972. Its totient is φ = 8372272.

The previous prime is 8421079. The next prime is 8421143. The reversal of 8421121 is 1211248.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6350400 + 2070721 = 2520^2 + 1439^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8421121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8421191) 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, 24166 + ... + 24511.

It is an arithmetic number, because the mean of its divisors is an integer number (2117493).

Almost surely, 2^8421121 is an apocalyptic number.

It is an amenable number.

8421121 is a deficient number, since it is larger than the sum of its proper divisors (48851).

8421121 is a wasteful number, since it uses less digits than its factorization.

8421121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48850.

The product of its digits is 128, while the sum is 19.

The square root of 8421121 is about 2901.9167803367. The cubic root of 8421121 is about 203.4495042205.

Adding to 8421121 its reverse (1211248), we get a palindrome (9632369).

The spelling of 8421121 in words is "eight million, four hundred twenty-one thousand, one hundred twenty-one".