8421904 has 20 divisors (see below), whose sum is σ = 16586860. Its totient is φ = 4141440.

The previous prime is 8421901. The next prime is 8421911. The reversal of 8421904 is 4091248.

It can be written as a sum of positive squares in 2 ways, for example, as 2890000 + 5531904 = 1700^2 + 2352^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8421901) 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, 3339 + ... + 5290.

It is an arithmetic number, because the mean of its divisors is an integer number (829343).

Almost surely, 2^8421904 is an apocalyptic number.

It is an amenable number.

8421904 is a deficient number, since it is larger than the sum of its proper divisors (8164956).

8421904 is a wasteful number, since it uses less digits than its factorization.

8421904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8698 (or 8692 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 8421904 is about 2902.0516880304. The cubic root of 8421904 is about 203.4558096369.

The spelling of 8421904 in words is "eight million, four hundred twenty-one thousand, nine hundred four".