221910439 has 2 divisors, whose sum is σ = 221910440. Its totient is φ = 221910438.

The previous prime is 221910421. The next prime is 221910449. The reversal of 221910439 is 934019122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221910439 - 2⁹ = 221909927 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221910439.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221910449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110955219 + 110955220.

It is an arithmetic number, because the mean of its divisors is an integer number (110955220).

Almost surely, 2^221910439 is an apocalyptic number.

221910439 is a deficient number, since it is larger than the sum of its proper divisors (1).

221910439 is an equidigital number, since it uses as much as digits as its factorization.

221910439 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 221910439 is about 14896.6586521945. The cubic root of 221910439 is about 605.4234578372.

The spelling of 221910439 in words is "two hundred twenty-one million, nine hundred ten thousand, four hundred thirty-nine".