7522221 has 8 divisors (see below), whose sum is σ = 11462464. Its totient is φ = 4298400.

The previous prime is 7522217. The next prime is 7522231. The reversal of 7522221 is 1222257.

It is a happy number.

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

It is not a de Polignac number, because 7522221 - 2² = 7522217 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 358201 = 7522221 / (7 + 5 + 2 + 2 + 2 + 2 + 1).

It is a Duffinian number.

It is a Curzon number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7522201) 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, 179080 + ... + 179121.

It is an arithmetic number, because the mean of its divisors is an integer number (1432808).

Almost surely, 2^7522221 is an apocalyptic number.

It is an amenable number.

7522221 is a deficient number, since it is larger than the sum of its proper divisors (3940243).

7522221 is a wasteful number, since it uses less digits than its factorization.

7522221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 358211.

The product of its digits is 560, while the sum is 21.

The square root of 7522221 is about 2742.6667679468. Note that the first 3 decimals coincide. The cubic root of 7522221 is about 195.9365076172.

Adding to 7522221 its reverse (1222257), we get a palindrome (8744478).

The spelling of 7522221 in words is "seven million, five hundred twenty-two thousand, two hundred twenty-one".