117171721 has 2 divisors, whose sum is σ = 117171722. Its totient is φ = 117171720.

The previous prime is 117171679. The next prime is 117171731. The reversal of 117171721 is 127171711.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 92371321 + 24800400 = 9611^2 + 4980^2 .

It is a cyclic number.

It is not a de Polignac number, because 117171721 - 2⁹ = 117171209 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 117171721.

It is not a weakly prime, because it can be changed into another prime (117171731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 58585860 + 58585861.

It is an arithmetic number, because the mean of its divisors is an integer number (58585861).

Almost surely, 2^117171721 is an apocalyptic number.

It is an amenable number.

117171721 is a deficient number, since it is larger than the sum of its proper divisors (1).

117171721 is an equidigital number, since it uses as much as digits as its factorization.

117171721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 686, while the sum is 28.

The square root of 117171721 is about 10824.5887219792. The cubic root of 117171721 is about 489.3364905348.

The spelling of 117171721 in words is "one hundred seventeen million, one hundred seventy-one thousand, seven hundred twenty-one".