72180117 has 18 divisors (see below), whose sum is σ = 106501122. Its totient is φ = 47090784.

The previous prime is 72180103. The next prime is 72180161. The reversal of 72180117 is 71108127.

It can be written as a sum of positive squares in 3 ways, for example, as 3721041 + 68459076 = 1929^2 + 8274^2 .

It is not a de Polignac number, because 72180117 - 2¹⁵ = 72147349 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72180197) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 185359 + ... + 185747.

It is an arithmetic number, because the mean of its divisors is an integer number (5916729).

Almost surely, 2^72180117 is an apocalyptic number.

It is an amenable number.

72180117 is a deficient number, since it is larger than the sum of its proper divisors (34321005).

72180117 is an equidigital number, since it uses as much as digits as its factorization.

72180117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 837 (or 445 counting only the distinct ones).

The product of its (nonzero) digits is 784, while the sum is 27.

The square root of 72180117 is about 8495.8882407904. Note that the first 3 decimals coincide. The cubic root of 72180117 is about 416.3633817151.

The spelling of 72180117 in words is "seventy-two million, one hundred eighty thousand, one hundred seventeen".