1717172221 has 2 divisors, whose sum is σ = 1717172222. Its totient is φ = 1717172220.

The previous prime is 1717172201. The next prime is 1717172231. The reversal of 1717172221 is 1222717171.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1173816121 + 543356100 = 34261^2 + 23310^2 .

It is a cyclic number.

It is not a de Polignac number, because 1717172221 - 2¹¹ = 1717170173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1717172201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 858586110 + 858586111.

It is an arithmetic number, because the mean of its divisors is an integer number (858586111).

Almost surely, 2^1717172221 is an apocalyptic number.

It is an amenable number.

1717172221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1717172221 is an equidigital number, since it uses as much as digits as its factorization.

1717172221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2744, while the sum is 31.

The square root of 1717172221 is about 41438.7767797265. The cubic root of 1717172221 is about 1197.4883162142.

Adding to 1717172221 its reverse (1222717171), we get a palindrome (2939889392).

The spelling of 1717172221 in words is "one billion, seven hundred seventeen million, one hundred seventy-two thousand, two hundred twenty-one".