72256181 has 2 divisors, whose sum is σ = 72256182. Its totient is φ = 72256180.

The previous prime is 72256127. The next prime is 72256187. The reversal of 72256181 is 18165227.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36663025 + 35593156 = 6055^2 + 5966^2 .

It is an emirp because it is prime and its reverse (18165227) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72256181 is a prime.

It is a super-2 number, since 2×72256181² = 10441911385409522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72256187) 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, 36128090 + 36128091.

It is an arithmetic number, because the mean of its divisors is an integer number (36128091).

Almost surely, 2^72256181 is an apocalyptic number.

It is an amenable number.

72256181 is a deficient number, since it is larger than the sum of its proper divisors (1).

72256181 is an equidigital number, since it uses as much as digits as its factorization.

72256181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6720, while the sum is 32.

The square root of 72256181 is about 8500.3635804594. The cubic root of 72256181 is about 416.5095860869.

The spelling of 72256181 in words is "seventy-two million, two hundred fifty-six thousand, one hundred eighty-one".