8421428 has 6 divisors (see below), whose sum is σ = 14737506. Its totient is φ = 4210712.

The previous prime is 8421419. The next prime is 8421463. The reversal of 8421428 is 8241248.

It can be written as a sum of positive squares in only one way, i.e., 6853924 + 1567504 = 2618^2 + 1252^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 8421428.

It is a congruent number.

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 as a sum of consecutive naturals, namely, 1052675 + ... + 1052682.

It is an arithmetic number, because the mean of its divisors is an integer number (2456251).

Almost surely, 2^8421428 is an apocalyptic number.

It is an amenable number.

8421428 is a deficient number, since it is larger than the sum of its proper divisors (6316078).

8421428 is a wasteful number, since it uses less digits than its factorization.

8421428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2105361 (or 2105359 counting only the distinct ones).

The product of its digits is 4096, while the sum is 29.

The square root of 8421428 is about 2901.9696759270. The cubic root of 8421428 is about 203.4519765057.

It can be divided in two parts, 84 and 21428, that added together give a palindrome (21512).

The spelling of 8421428 in words is "eight million, four hundred twenty-one thousand, four hundred twenty-eight".