72517231 has 2 divisors, whose sum is σ = 72517232. Its totient is φ = 72517230.

The previous prime is 72517219. The next prime is 72517267. The reversal of 72517231 is 13271527.

It is a weak prime.

It is an emirp because it is prime and its reverse (13271527) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72517231 - 2¹⁵ = 72484463 is a prime.

It is a super-2 number, since 2×72517231² = 10517497583814722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 72517231.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72517931) 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, 36258615 + 36258616.

It is an arithmetic number, because the mean of its divisors is an integer number (36258616).

Almost surely, 2^72517231 is an apocalyptic number.

72517231 is a deficient number, since it is larger than the sum of its proper divisors (1).

72517231 is an equidigital number, since it uses as much as digits as its factorization.

72517231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2940, while the sum is 28.

The square root of 72517231 is about 8515.7049620099. The cubic root of 72517231 is about 417.0105773607.

Adding to 72517231 its reverse (13271527), we get a palindrome (85788758).

It can be divided in two parts, 725 and 17231, that added together give a square (17956 = 134²).

The spelling of 72517231 in words is "seventy-two million, five hundred seventeen thousand, two hundred thirty-one".