221908433 has 2 divisors, whose sum is σ = 221908434. Its totient is φ = 221908432.

The previous prime is 221908411. The next prime is 221908451. The reversal of 221908433 is 334809122.

It is a happy number.

221908433 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 124925329 + 96983104 = 11177^2 + 9848^2 .

It is a cyclic number.

It is not a de Polignac number, because 221908433 - 2⁸ = 221908177 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221908433.

It is not a weakly prime, because it can be changed into another prime (221908133) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110954216 + 110954217.

It is an arithmetic number, because the mean of its divisors is an integer number (110954217).

Almost surely, 2^221908433 is an apocalyptic number.

It is an amenable number.

221908433 is a deficient number, since it is larger than the sum of its proper divisors (1).

221908433 is an equidigital number, since it uses as much as digits as its factorization.

221908433 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 221908433 is about 14896.5913215071. The cubic root of 221908433 is about 605.4216335530.

The spelling of 221908433 in words is "two hundred twenty-one million, nine hundred eight thousand, four hundred thirty-three".