172111729 has 2 divisors, whose sum is σ = 172111730. Its totient is φ = 172111728.

The previous prime is 172111631. The next prime is 172111759. The reversal of 172111729 is 927111271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 102556129 + 69555600 = 10127^2 + 8340^2 .

It is an emirp because it is prime and its reverse (927111271) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 172111729 - 2¹⁵ = 172078961 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 172111729.

It is not a weakly prime, because it can be changed into another prime (172111759) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86055864 + 86055865.

It is an arithmetic number, because the mean of its divisors is an integer number (86055865).

Almost surely, 2^172111729 is an apocalyptic number.

It is an amenable number.

172111729 is a deficient number, since it is larger than the sum of its proper divisors (1).

172111729 is an equidigital number, since it uses as much as digits as its factorization.

172111729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1764, while the sum is 31.

The square root of 172111729 is about 13119.1359852698. The cubic root of 172111729 is about 556.2501688507.

The spelling of 172111729 in words is "one hundred seventy-two million, one hundred eleven thousand, seven hundred twenty-nine".