7221136 has 40 divisors (see below), whose sum is σ = 15233400. Its totient is φ = 3296256.

The previous prime is 7221131. The next prime is 7221143. The reversal of 7221136 is 6311227.

It can be written as a sum of positive squares in 4 ways, for example, as 230400 + 6990736 = 480^2 + 2644^2 .

It is not an unprimeable number, because it can be changed into a prime (7221131) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30876 + ... + 31108.

It is an arithmetic number, because the mean of its divisors is an integer number (380835).

Almost surely, 2^7221136 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 7221136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7616700).

7221136 is an abundant number, since it is smaller than the sum of its proper divisors (8012264).

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

7221136 is a wasteful number, since it uses less digits than its factorization.

7221136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 403 (or 397 counting only the distinct ones).

The product of its digits is 504, while the sum is 22.

The square root of 7221136 is about 2687.2171479060. The cubic root of 7221136 is about 193.2866421796.

Subtracting from 7221136 its reverse (6311227), we obtain a palindrome (909909).

The spelling of 7221136 in words is "seven million, two hundred twenty-one thousand, one hundred thirty-six".