7891128 has 128 divisors (see below), whose sum is σ = 26611200. Its totient is φ = 2115072.

The previous prime is 7891123. The next prime is 7891141. The reversal of 7891128 is 8211987.

It is a super-2 number, since 2×7891128² = 124539802224768, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

Its product of digits (8064) is a multiple of the sum of its prime divisors (336).

It is a junction number, because it is equal to n+sod(n) for n = 7891092 and 7891101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7891123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 25551 + ... + 25857.

It is an arithmetic number, because the mean of its divisors is an integer number (207900).

Almost surely, 2^7891128 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7891128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13305600).

7891128 is an abundant number, since it is smaller than the sum of its proper divisors (18720072).

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

7891128 is a wasteful number, since it uses less digits than its factorization.

7891128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 346 (or 336 counting only the distinct ones).

The product of its digits is 8064, while the sum is 36.

The square root of 7891128 is about 2809.1151631786. The cubic root of 7891128 is about 199.0885862674.

The spelling of 7891128 in words is "seven million, eight hundred ninety-one thousand, one hundred twenty-eight".