221554841 has 2 divisors, whose sum is σ = 221554842. Its totient is φ = 221554840.

The previous prime is 221554819. The next prime is 221554871. The reversal of 221554841 is 148455122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 138744841 + 82810000 = 11779^2 + 9100^2 .

It is a cyclic number.

It is not a de Polignac number, because 221554841 - 2¹⁸ = 221292697 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 221554798 and 221554807.

It is not a weakly prime, because it can be changed into another prime (221554811) 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, 110777420 + 110777421.

It is an arithmetic number, because the mean of its divisors is an integer number (110777421).

Almost surely, 2^221554841 is an apocalyptic number.

It is an amenable number.

221554841 is a deficient number, since it is larger than the sum of its proper divisors (1).

221554841 is an equidigital number, since it uses as much as digits as its factorization.

221554841 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12800, while the sum is 32.

The square root of 221554841 is about 14884.7183715380. The cubic root of 221554841 is about 605.0999001755.

The spelling of 221554841 in words is "two hundred twenty-one million, five hundred fifty-four thousand, eight hundred forty-one".