8175421 has 4 divisors (see below), whose sum is σ = 8196412. Its totient is φ = 8154432.

The previous prime is 8175397. The next prime is 8175439. The reversal of 8175421 is 1245718.

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 6996025 + 1179396 = 2645^2 + 1086^2 .

It is a cyclic number.

It is not a de Polignac number, because 8175421 - 2⁵ = 8175389 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 8175421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8175821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9900 + ... + 10693.

It is an arithmetic number, because the mean of its divisors is an integer number (2049103).

Almost surely, 2^8175421 is an apocalyptic number.

It is an amenable number.

8175421 is a deficient number, since it is larger than the sum of its proper divisors (20991).

8175421 is a wasteful number, since it uses less digits than its factorization.

8175421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20990.

The product of its digits is 2240, while the sum is 28.

The square root of 8175421 is about 2859.2693122544. The cubic root of 8175421 is about 201.4512850523.

The spelling of 8175421 in words is "eight million, one hundred seventy-five thousand, four hundred twenty-one".