7728840 has 96 divisors (see below), whose sum is σ = 28716480. Its totient is φ = 1766016.

The previous prime is 7728803. The next prime is 7728841. The reversal of 7728840 is 488277.

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

It is a junction number, because it is equal to n+sod(n) for n = 7728795 and 7728804.

It is not an unprimeable number, because it can be changed into a prime (7728841) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 987 + ... + 4053.

It is an arithmetic number, because the mean of its divisors is an integer number (299130).

Almost surely, 2^7728840 is an apocalyptic number.

7728840 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7728840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14358240).

7728840 is an abundant number, since it is smaller than the sum of its proper divisors (20987640).

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

7728840 is a wasteful number, since it uses less digits than its factorization.

7728840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3091 (or 3084 counting only the distinct ones).

The product of its (nonzero) digits is 25088, while the sum is 36.

The square root of 7728840 is about 2780.0791355643. The cubic root of 7728840 is about 197.7143109725.

The spelling of 7728840 in words is "seven million, seven hundred twenty-eight thousand, eight hundred forty".