72017129 has 4 divisors (see below), whose sum is σ = 72193620. Its totient is φ = 71840640.

The previous prime is 72017107. The next prime is 72017147. The reversal of 72017129 is 92171027.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 92171027 = 13 ⋅7090079.

It can be written as a sum of positive squares in 2 ways, for example, as 66504025 + 5513104 = 8155^2 + 2348^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72017129 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (72017159) 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 in 3 ways as a sum of consecutive naturals, for example, 87632 + ... + 88449.

It is an arithmetic number, because the mean of its divisors is an integer number (18048405).

Almost surely, 2^72017129 is an apocalyptic number.

It is an amenable number.

72017129 is a deficient number, since it is larger than the sum of its proper divisors (176491).

72017129 is a wasteful number, since it uses less digits than its factorization.

72017129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176490.

The product of its (nonzero) digits is 1764, while the sum is 29.

The square root of 72017129 is about 8486.2906502193. The cubic root of 72017129 is about 416.0497525092.

The spelling of 72017129 in words is "seventy-two million, seventeen thousand, one hundred twenty-nine".