72771161 has 2 divisors, whose sum is σ = 72771162. Its totient is φ = 72771160.

The previous prime is 72771143. The next prime is 72771199. The reversal of 72771161 is 16117727.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48219136 + 24552025 = 6944^2 + 4955^2 .

It is an emirp because it is prime and its reverse (16117727) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72771161 - 2¹⁴ = 72754777 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (72771961) 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, 36385580 + 36385581.

It is an arithmetic number, because the mean of its divisors is an integer number (36385581).

Almost surely, 2^72771161 is an apocalyptic number.

It is an amenable number.

72771161 is a deficient number, since it is larger than the sum of its proper divisors (1).

72771161 is an equidigital number, since it uses as much as digits as its factorization.

72771161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4116, while the sum is 32.

The square root of 72771161 is about 8530.6014442125. The cubic root of 72771161 is about 417.4967520992.

Adding to 72771161 its reverse (16117727), we get a palindrome (88888888).

The spelling of 72771161 in words is "seventy-two million, seven hundred seventy-one thousand, one hundred sixty-one".