7222721 has 16 divisors (see below), whose sum is σ = 8294400. Its totient is φ = 6229200.

The previous prime is 7222687. The next prime is 7222723. The reversal of 7222721 is 1272227.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7222721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7222723) 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, 19940 + ... + 20298.

It is an arithmetic number, because the mean of its divisors is an integer number (518400).

Almost surely, 2^7222721 is an apocalyptic number.

It is an amenable number.

7222721 is a deficient number, since it is larger than the sum of its proper divisors (1071679).

7222721 is a wasteful number, since it uses less digits than its factorization.

7222721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 460.

The product of its digits is 784, while the sum is 23.

The square root of 7222721 is about 2687.5120464846. The cubic root of 7222721 is about 193.3007829333.

Adding to 7222721 its reverse (1272227), we get a palindrome (8494948).

It can be divided in two parts, 722 and 2721, that added together give a palindrome (3443).

The spelling of 7222721 in words is "seven million, two hundred twenty-two thousand, seven hundred twenty-one".