72217 has 4 divisors (see below), whose sum is σ = 72756. Its totient is φ = 71680.

The previous prime is 72211. The next prime is 72221. The reversal of 72217 is 71227.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 71227 = 13 ⋅5479.

It can be written as a sum of positive squares in 2 ways, for example, as 63001 + 9216 = 251^2 + 96^2 .

It is a cyclic number.

It is not a de Polignac number, because 72217 - 2⁷ = 72089 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 72194 and 72203.

It is not an unprimeable number, because it can be changed into a prime (72211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 117 + ... + 397.

It is an arithmetic number, because the mean of its divisors is an integer number (18189).

2⁷²²¹⁷ is an apocalyptic number.

It is an amenable number.

72217 is a deficient number, since it is larger than the sum of its proper divisors (539).

72217 is a wasteful number, since it uses less digits than its factorization.

72217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 538.

The product of its digits is 196, while the sum is 19.

The square root of 72217 is about 268.7322087134. The cubic root of 72217 is about 41.6434288202.

Subtracting from 72217 its reverse (71227), we obtain a triangular number (990 = T₄₄).

It can be divided in two parts, 72 and 217, that added together give a square (289 = 17²).

The spelling of 72217 in words is "seventy-two thousand, two hundred seventeen", and thus it is an iban number.