221853378209 has 2 divisors, whose sum is σ = 221853378210. Its totient is φ = 221853378208.

The previous prime is 221853378167. The next prime is 221853378233. The reversal of 221853378209 is 902873358122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 122976462400 + 98876915809 = 350680^2 + 314447^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221853378209 is a prime.

It is not a weakly prime, because it can be changed into another prime (221853374209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110926689104 + 110926689105.

It is an arithmetic number, because the mean of its divisors is an integer number (110926689105).

Almost surely, 2^221853378209 is an apocalyptic number.

It is an amenable number.

221853378209 is a deficient number, since it is larger than the sum of its proper divisors (1).

221853378209 is an equidigital number, since it uses as much as digits as its factorization.

221853378209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1451520, while the sum is 50.

The spelling of 221853378209 in words is "two hundred twenty-one billion, eight hundred fifty-three million, three hundred seventy-eight thousand, two hundred nine".