72109231 has 2 divisors, whose sum is σ = 72109232. Its totient is φ = 72109230.

The previous prime is 72109217. The next prime is 72109243. The reversal of 72109231 is 13290127.

It is a strong prime.

It is an emirp because it is prime and its reverse (13290127) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72109231 - 2⁹ = 72108719 is a prime.

It is a super-2 number, since 2×72109231² = 10399482390822722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 72109196 and 72109205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72103231) 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, 36054615 + 36054616.

It is an arithmetic number, because the mean of its divisors is an integer number (36054616).

Almost surely, 2^72109231 is an apocalyptic number.

72109231 is a deficient number, since it is larger than the sum of its proper divisors (1).

72109231 is an equidigital number, since it uses as much as digits as its factorization.

72109231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 72109231 is about 8491.7154332914. The cubic root of 72109231 is about 416.2270376040.

Adding to 72109231 its reverse (13290127), we get a palindrome (85399358).

The spelling of 72109231 in words is "seventy-two million, one hundred nine thousand, two hundred thirty-one".