221544413 has 2 divisors, whose sum is σ = 221544414. Its totient is φ = 221544412.

The previous prime is 221544359. The next prime is 221544431. The reversal of 221544413 is 314445122.

Together with next prime (221544431) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 184905604 + 36638809 = 13598^2 + 6053^2 .

It is a cyclic number.

It is not a de Polignac number, because 221544413 - 2¹⁴ = 221528029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221544473) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110772206 + 110772207.

It is an arithmetic number, because the mean of its divisors is an integer number (110772207).

Almost surely, 2^221544413 is an apocalyptic number.

It is an amenable number.

221544413 is a deficient number, since it is larger than the sum of its proper divisors (1).

221544413 is an equidigital number, since it uses as much as digits as its factorization.

221544413 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3840, while the sum is 26.

The square root of 221544413 is about 14884.3680752661. The cubic root of 221544413 is about 605.0904065429.

Adding to 221544413 its reverse (314445122), we get a palindrome (535989535).

The spelling of 221544413 in words is "two hundred twenty-one million, five hundred forty-four thousand, four hundred thirteen".