172981181 has 2 divisors, whose sum is σ = 172981182. Its totient is φ = 172981180.

The previous prime is 172981153. The next prime is 172981199. The reversal of 172981181 is 181189271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 155625625 + 17355556 = 12475^2 + 4166^2 .

It is an emirp because it is prime and its reverse (181189271) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 172981181 - 2⁶ = 172981117 is a prime.

It is a super-2 number, since 2×172981181² = 59844977960309522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172981141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86490590 + 86490591.

It is an arithmetic number, because the mean of its divisors is an integer number (86490591).

Almost surely, 2^172981181 is an apocalyptic number.

It is an amenable number.

172981181 is a deficient number, since it is larger than the sum of its proper divisors (1).

172981181 is an equidigital number, since it uses as much as digits as its factorization.

172981181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 38.

The square root of 172981181 is about 13152.2310274721. The cubic root of 172981181 is about 557.1852604870.

The spelling of 172981181 in words is "one hundred seventy-two million, nine hundred eighty-one thousand, one hundred eighty-one".