221717317 has 2 divisors, whose sum is σ = 221717318. Its totient is φ = 221717316.

The previous prime is 221717303. The next prime is 221717329. The reversal of 221717317 is 713717122.

It is a happy number.

221717317 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., 218034756 + 3682561 = 14766^2 + 1919^2 .

It is a cyclic number.

It is not a de Polignac number, because 221717317 - 2¹¹ = 221715269 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221717347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110858658 + 110858659.

It is an arithmetic number, because the mean of its divisors is an integer number (110858659).

Almost surely, 2^221717317 is an apocalyptic number.

It is an amenable number.

221717317 is a deficient number, since it is larger than the sum of its proper divisors (1).

221717317 is an equidigital number, since it uses as much as digits as its factorization.

221717317 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4116, while the sum is 31.

The square root of 221717317 is about 14890.1751836572. The cubic root of 221717317 is about 605.2477795719.

The spelling of 221717317 in words is "two hundred twenty-one million, seven hundred seventeen thousand, three hundred seventeen".