72706181 has 2 divisors, whose sum is σ = 72706182. Its totient is φ = 72706180.

The previous prime is 72706177. The next prime is 72706187. The reversal of 72706181 is 18160727.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38950081 + 33756100 = 6241^2 + 5810^2 .

It is a cyclic number.

It is not a de Polignac number, because 72706181 - 2² = 72706177 is a prime.

It is a super-2 number, since 2×72706181² = 10572377511209522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72706187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36353090 + 36353091.

It is an arithmetic number, because the mean of its divisors is an integer number (36353091).

Almost surely, 2^72706181 is an apocalyptic number.

It is an amenable number.

72706181 is a deficient number, since it is larger than the sum of its proper divisors (1).

72706181 is an equidigital number, since it uses as much as digits as its factorization.

72706181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4704, while the sum is 32.

The square root of 72706181 is about 8526.7919524285. The cubic root of 72706181 is about 417.3724491135.

The spelling of 72706181 in words is "seventy-two million, seven hundred six thousand, one hundred eighty-one".