7898221 has 2 divisors, whose sum is σ = 7898222. Its totient is φ = 7898220.

The previous prime is 7898213. The next prime is 7898239. The reversal of 7898221 is 1228987.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5692996 + 2205225 = 2386^2 + 1485^2 .

It is an emirp because it is prime and its reverse (1228987) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7898221 - 2³ = 7898213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7898291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3949110 + 3949111.

It is an arithmetic number, because the mean of its divisors is an integer number (3949111).

Almost surely, 2^7898221 is an apocalyptic number.

It is an amenable number.

7898221 is a deficient number, since it is larger than the sum of its proper divisors (1).

7898221 is an equidigital number, since it uses as much as digits as its factorization.

7898221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16128, while the sum is 37.

The square root of 7898221 is about 2810.3773767948. The cubic root of 7898221 is about 199.1482191636.

It can be divided in two parts, 78982 and 21, that added together give a triangular number (79003 = T₃₉₇).

The spelling of 7898221 in words is "seven million, eight hundred ninety-eight thousand, two hundred twenty-one".