7780728 has 64 divisors (see below), whose sum is σ = 20793600. Its totient is φ = 2419200.

The previous prime is 7780727. The next prime is 7780741. The reversal of 7780728 is 8270877.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7780727) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51453 + ... + 51603.

It is an arithmetic number, because the mean of its divisors is an integer number (324900).

Almost surely, 2^7780728 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 7780728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10396800).

7780728 is an abundant number, since it is smaller than the sum of its proper divisors (13012872).

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

7780728 is a wasteful number, since it uses less digits than its factorization.

7780728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292 (or 288 counting only the distinct ones).

The product of its (nonzero) digits is 43904, while the sum is 39.

The square root of 7780728 is about 2789.3956334661. The cubic root of 7780728 is about 198.1557798643.

The spelling of 7780728 in words is "seven million, seven hundred eighty thousand, seven hundred twenty-eight".