221800841 has 2 divisors, whose sum is σ = 221800842. Its totient is φ = 221800840.

The previous prime is 221800793. The next prime is 221800861. The reversal of 221800841 is 148008122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 216207616 + 5593225 = 14704^2 + 2365^2 .

It is a cyclic number.

It is not a de Polignac number, because 221800841 - 2¹⁰ = 221799817 is a prime.

It is a super-2 number, since 2×221800841² = 98391226136614562, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 221800841.

It is not a weakly prime, because it can be changed into another prime (221800861) 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, 110900420 + 110900421.

It is an arithmetic number, because the mean of its divisors is an integer number (110900421).

Almost surely, 2^221800841 is an apocalyptic number.

It is an amenable number.

221800841 is a deficient number, since it is larger than the sum of its proper divisors (1).

221800841 is an equidigital number, since it uses as much as digits as its factorization.

221800841 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1024, while the sum is 26.

The square root of 221800841 is about 14892.9795877118. The cubic root of 221800841 is about 605.3237717851.

Adding to 221800841 its reverse (148008122), we get a palindrome (369808963).

The spelling of 221800841 in words is "two hundred twenty-one million, eight hundred thousand, eight hundred forty-one".