1005216221 has 2 divisors, whose sum is σ = 1005216222. Its totient is φ = 1005216220.

The previous prime is 1005216187. The next prime is 1005216257. The reversal of 1005216221 is 1226125001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 936972100 + 68244121 = 30610^2 + 8261^2 .

It is an emirp because it is prime and its reverse (1226125001) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1005216221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1005216193 and 1005216202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1005216281) 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, 502608110 + 502608111.

It is an arithmetic number, because the mean of its divisors is an integer number (502608111).

Almost surely, 2^1005216221 is an apocalyptic number.

It is an amenable number.

1005216221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1005216221 is an equidigital number, since it uses as much as digits as its factorization.

1005216221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 1005216221 is about 31705.1450241124. The cubic root of 1005216221 is about 1001.7357258460.

The spelling of 1005216221 in words is "one billion, five million, two hundred sixteen thousand, two hundred twenty-one".