8278921 has 4 divisors (see below), whose sum is σ = 9461632. Its totient is φ = 7096212.

The previous prime is 8278883. The next prime is 8278931. The reversal of 8278921 is 1298728.

8278921 is nontrivially palindromic in base 13.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 8278921 - 2⁷ = 8278793 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8278931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 591345 + ... + 591358.

It is an arithmetic number, because the mean of its divisors is an integer number (2365408).

Almost surely, 2^8278921 is an apocalyptic number.

It is an amenable number.

8278921 is a deficient number, since it is larger than the sum of its proper divisors (1182711).

8278921 is a wasteful number, since it uses less digits than its factorization.

8278921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1182710.

The product of its digits is 16128, while the sum is 37.

The square root of 8278921 is about 2877.3114186685. The cubic root of 8278921 is about 202.2978402122.

It can be divided in two parts, 82 and 78921, that added together give a triangular number (79003 = T₃₉₇).

The spelling of 8278921 in words is "eight million, two hundred seventy-eight thousand, nine hundred twenty-one".