8421425 has 6 divisors (see below), whose sum is σ = 10442598. Its totient is φ = 6737120.

The previous prime is 8421419. The next prime is 8421463. The reversal of 8421425 is 5241248.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 1682209 + 6739216 = 1297^2 + 2596^2 .

It is a de Polignac number, because none of the positive numbers 2^k-8421425 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 8421394 and 8421403.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 168404 + ... + 168453.

It is an arithmetic number, because the mean of its divisors is an integer number (1740433).

Almost surely, 2^8421425 is an apocalyptic number.

It is an amenable number.

8421425 is a deficient number, since it is larger than the sum of its proper divisors (2021173).

8421425 is a wasteful number, since it uses less digits than its factorization.

8421425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 336867 (or 336862 counting only the distinct ones).

The product of its digits is 2560, while the sum is 26.

The square root of 8421425 is about 2901.9691590367. The cubic root of 8421425 is about 203.4519523468.

The spelling of 8421425 in words is "eight million, four hundred twenty-one thousand, four hundred twenty-five".