221501207 has 2 divisors, whose sum is σ = 221501208. Its totient is φ = 221501206.

The previous prime is 221501197. The next prime is 221501237. The reversal of 221501207 is 702105122.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221501207 - 2¹⁸ = 221239063 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221501237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110750603 + 110750604.

It is an arithmetic number, because the mean of its divisors is an integer number (110750604).

Almost surely, 2^221501207 is an apocalyptic number.

221501207 is a deficient number, since it is larger than the sum of its proper divisors (1).

221501207 is an equidigital number, since it uses as much as digits as its factorization.

221501207 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 280, while the sum is 20.

The square root of 221501207 is about 14882.9166160400. The cubic root of 221501207 is about 605.0510687033.

Adding to 221501207 its reverse (702105122), we get a palindrome (923606329).

The spelling of 221501207 in words is "two hundred twenty-one million, five hundred one thousand, two hundred seven".