221705711 has 2 divisors, whose sum is σ = 221705712. Its totient is φ = 221705710.

The previous prime is 221705689. The next prime is 221705713. The reversal of 221705711 is 117507122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221705711 - 2⁶ = 221705647 is a prime.

Together with 221705713, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221705713) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110852855 + 110852856.

It is an arithmetic number, because the mean of its divisors is an integer number (110852856).

Almost surely, 2^221705711 is an apocalyptic number.

221705711 is a deficient number, since it is larger than the sum of its proper divisors (1).

221705711 is an equidigital number, since it uses as much as digits as its factorization.

221705711 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 980, while the sum is 26.

The square root of 221705711 is about 14889.7854584947. The cubic root of 221705711 is about 605.2372186342.

The spelling of 221705711 in words is "two hundred twenty-one million, seven hundred five thousand, seven hundred eleven".