221990507 has 2 divisors, whose sum is σ = 221990508. Its totient is φ = 221990506.

The previous prime is 221990501. The next prime is 221990519. The reversal of 221990507 is 705099122.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221990507 - 2¹⁸ = 221728363 is a prime.

It is not a weakly prime, because it can be changed into another prime (221990501) 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, 110995253 + 110995254.

It is an arithmetic number, because the mean of its divisors is an integer number (110995254).

Almost surely, 2^221990507 is an apocalyptic number.

221990507 is a deficient number, since it is larger than the sum of its proper divisors (1).

221990507 is an equidigital number, since it uses as much as digits as its factorization.

221990507 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11340, while the sum is 35.

The square root of 221990507 is about 14899.3458581241. The cubic root of 221990507 is about 605.4962638104.

The spelling of 221990507 in words is "two hundred twenty-one million, nine hundred ninety thousand, five hundred seven".