5521721 has 2 divisors, whose sum is σ = 5521722. Its totient is φ = 5521720.

The previous prime is 5521709. The next prime is 5521729. The reversal of 5521721 is 1271255.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5112121 + 409600 = 2261^2 + 640^2 .

It is a cyclic number.

It is not a de Polignac number, because 5521721 - 2⁶ = 5521657 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (5521729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2760860 + 2760861.

It is an arithmetic number, because the mean of its divisors is an integer number (2760861).

Almost surely, 2^5521721 is an apocalyptic number.

It is an amenable number.

5521721 is a deficient number, since it is larger than the sum of its proper divisors (1).

5521721 is an equidigital number, since it uses as much as digits as its factorization.

5521721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 700, while the sum is 23.

The square root of 5521721 is about 2349.8342494738. The cubic root of 5521721 is about 176.7494833425.

Adding to 5521721 its reverse (1271255), we get a palindrome (6792976).

The spelling of 5521721 in words is "five million, five hundred twenty-one thousand, seven hundred twenty-one".