7887644221 has 2 divisors, whose sum is σ = 7887644222. Its totient is φ = 7887644220.

The previous prime is 7887644189. The next prime is 7887644227. The reversal of 7887644221 is 1224467887.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4408296025 + 3479348196 = 66395^2 + 58986^2 .

It is a cyclic number.

It is not a de Polignac number, because 7887644221 - 2⁵ = 7887644189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7887644227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3943822110 + 3943822111.

It is an arithmetic number, because the mean of its divisors is an integer number (3943822111).

Almost surely, 2^7887644221 is an apocalyptic number.

It is an amenable number.

7887644221 is a deficient number, since it is larger than the sum of its proper divisors (1).

7887644221 is an equidigital number, since it uses as much as digits as its factorization.

7887644221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1204224, while the sum is 49.

The square root of 7887644221 is about 88812.4102870764. The cubic root of 7887644221 is about 1990.5928404650.

The spelling of 7887644221 in words is "seven billion, eight hundred eighty-seven million, six hundred forty-four thousand, two hundred twenty-one".