72164446181 has 2 divisors, whose sum is σ = 72164446182. Its totient is φ = 72164446180.

The previous prime is 72164446177. The next prime is 72164446187. The reversal of 72164446181 is 18164446127.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66724056100 + 5440390081 = 258310^2 + 73759^2 .

It is a cyclic number.

It is not a de Polignac number, because 72164446181 - 2² = 72164446177 is a prime.

It is a super-2 number, since 2×72164446181² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72164446187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36082223090 + 36082223091.

It is an arithmetic number, because the mean of its divisors is an integer number (36082223091).

Almost surely, 2^72164446181 is an apocalyptic number.

It is an amenable number.

72164446181 is a deficient number, since it is larger than the sum of its proper divisors (1).

72164446181 is an equidigital number, since it uses as much as digits as its factorization.

72164446181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 258048, while the sum is 44.

The spelling of 72164446181 in words is "seventy-two billion, one hundred sixty-four million, four hundred forty-six thousand, one hundred eighty-one".