7921428 has 12 divisors (see below), whose sum is σ = 18483360. Its totient is φ = 2640472.

The previous prime is 7921411. The next prime is 7921447. The reversal of 7921428 is 8241297.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

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, 330048 + ... + 330071.

It is an arithmetic number, because the mean of its divisors is an integer number (1540280).

Almost surely, 2^7921428 is an apocalyptic number.

It is an amenable number.

7921428 is an abundant number, since it is smaller than the sum of its proper divisors (10561932).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7921428 is a wasteful number, since it uses less digits than its factorization.

7921428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 660126 (or 660124 counting only the distinct ones).

The product of its digits is 8064, while the sum is 33.

The square root of 7921428 is about 2814.5031533114. The cubic root of 7921428 is about 199.3430779630.

The spelling of 7921428 in words is "seven million, nine hundred twenty-one thousand, four hundred twenty-eight".