7887221 has 2 divisors, whose sum is σ = 7887222. Its totient is φ = 7887220.

The previous prime is 7887181. The next prime is 7887247. The reversal of 7887221 is 1227887.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7102225 + 784996 = 2665^2 + 886^2 .

It is an emirp because it is prime and its reverse (1227887) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7887221 - 2⁶ = 7887157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7887251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3943610 + 3943611.

It is an arithmetic number, because the mean of its divisors is an integer number (3943611).

Almost surely, 2^7887221 is an apocalyptic number.

It is an amenable number.

7887221 is a deficient number, since it is larger than the sum of its proper divisors (1).

7887221 is an equidigital number, since it uses as much as digits as its factorization.

7887221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12544, while the sum is 35.

The square root of 7887221 is about 2808.4196623724. The cubic root of 7887221 is about 199.0557237280.

The spelling of 7887221 in words is "seven million, eight hundred eighty-seven thousand, two hundred twenty-one".