7321128 has 16 divisors (see below), whose sum is σ = 18302880. Its totient is φ = 2440368.

The previous prime is 7321123. The next prime is 7321129. The reversal of 7321128 is 8211237.

It is a hoax number, since the sum of its digits (24) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 305047 = 7321128 / (7 + 3 + 2 + 1 + 1 + 2 + 8).

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 7321098 and 7321107.

It is not an unprimeable number, because it can be changed into a prime (7321121) 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, 152500 + ... + 152547.

It is an arithmetic number, because the mean of its divisors is an integer number (1143930).

Almost surely, 2^7321128 is an apocalyptic number.

It is an amenable number.

7321128 is an abundant number, since it is smaller than the sum of its proper divisors (10981752).

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

7321128 is a wasteful number, since it uses less digits than its factorization.

7321128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305056 (or 305052 counting only the distinct ones).

The product of its digits is 672, while the sum is 24.

The square root of 7321128 is about 2705.7583040619. The cubic root of 7321128 is about 194.1747106477.

The spelling of 7321128 in words is "seven million, three hundred twenty-one thousand, one hundred twenty-eight".