221936009 has 2 divisors, whose sum is σ = 221936010. Its totient is φ = 221936008.

The previous prime is 221935999. The next prime is 221936041. The reversal of 221936009 is 900639122.

It is an a-pointer prime, because the next prime (221936041) can be obtained adding 221936009 to its sum of digits (32).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 191905609 + 30030400 = 13853^2 + 5480^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221936009 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (221936509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110968004 + 110968005.

It is an arithmetic number, because the mean of its divisors is an integer number (110968005).

Almost surely, 2^221936009 is an apocalyptic number.

It is an amenable number.

221936009 is a deficient number, since it is larger than the sum of its proper divisors (1).

221936009 is an equidigital number, since it uses as much as digits as its factorization.

221936009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5832, while the sum is 32.

The square root of 221936009 is about 14897.5168736270. The cubic root of 221936009 is about 605.4467105862.

The spelling of 221936009 in words is "two hundred twenty-one million, nine hundred thirty-six thousand, nine".