7221561 has 8 divisors (see below), whose sum is σ = 9661344. Its totient is φ = 4798080.

The previous prime is 7221547. The next prime is 7221569. The reversal of 7221561 is 1651227.

7221561 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 7221561 - 2¹⁵ = 7188793 is a prime.

It is not an unprimeable number, because it can be changed into a prime (7221569) 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, 3000 + ... + 4841.

It is an arithmetic number, because the mean of its divisors is an integer number (1207668).

Almost surely, 2^7221561 is an apocalyptic number.

It is an amenable number.

7221561 is a deficient number, since it is larger than the sum of its proper divisors (2439783).

7221561 is a wasteful number, since it uses less digits than its factorization.

7221561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8151.

The product of its digits is 840, while the sum is 24.

The square root of 7221561 is about 2687.2962248327. The cubic root of 7221561 is about 193.2904340673.

Adding to 7221561 its reverse (1651227), we get a palindrome (8872788).

The spelling of 7221561 in words is "seven million, two hundred twenty-one thousand, five hundred sixty-one".