7221660 has 48 divisors (see below), whose sum is σ = 20773536. Its totient is φ = 1873152.

The previous prime is 7221649. The next prime is 7221661. The reversal of 7221660 is 661227.

It is a happy number.

7221660 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 7221660.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7221661) 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, 594 + ... + 3846.

It is an arithmetic number, because the mean of its divisors is an integer number (432782).

Almost surely, 2^7221660 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 7221660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10386768).

7221660 is an abundant number, since it is smaller than the sum of its proper divisors (13551876).

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

7221660 is a wasteful number, since it uses less digits than its factorization.

7221660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3302 (or 3300 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 7221660 is about 2687.3146447709. The cubic root of 7221660 is about 193.2913173328.

Adding to 7221660 its reverse (661227), we get a palindrome (7882887).

The spelling of 7221660 in words is "seven million, two hundred twenty-one thousand, six hundred sixty".