7720000 has 70 divisors (see below), whose sum is σ = 19242278. Its totient is φ = 3072000.

The previous prime is 7719997. The next prime is 7720001. The reversal of 7720000 is 277.

It can be written as a sum of positive squares in 5 ways, for example, as 4064256 + 3655744 = 2016^2 + 1912^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (7720001) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 39904 + ... + 40096.

Almost surely, 2^7720000 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 7720000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9621139).

7720000 is an abundant number, since it is smaller than the sum of its proper divisors (11522278).

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

7720000 is an equidigital number, since it uses as much as digits as its factorization.

7720000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225 (or 200 counting only the distinct ones).

The product of its (nonzero) digits is 98, while the sum is 16.

The square root of 7720000 is about 2778.4887978900. The cubic root of 7720000 is about 197.6389024467.

Adding to 7720000 its reverse (277), we get a palindrome (7720277).

The spelling of 7720000 in words is "seven million, seven hundred twenty thousand".