221423829509 has 2 divisors, whose sum is σ = 221423829510. Its totient is φ = 221423829508.

The previous prime is 221423829493. The next prime is 221423829521. The reversal of 221423829509 is 905928324122.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 210660804484 + 10763025025 = 458978^2 + 103745^2 .

It is a cyclic number.

It is not a de Polignac number, because 221423829509 - 2⁴ = 221423829493 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221423829709) 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, 110711914754 + 110711914755.

It is an arithmetic number, because the mean of its divisors is an integer number (110711914755).

Almost surely, 2^221423829509 is an apocalyptic number.

It is an amenable number.

221423829509 is a deficient number, since it is larger than the sum of its proper divisors (1).

221423829509 is an equidigital number, since it uses as much as digits as its factorization.

221423829509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 622080, while the sum is 47.

The spelling of 221423829509 in words is "two hundred twenty-one billion, four hundred twenty-three million, eight hundred twenty-nine thousand, five hundred nine".