867640181 has 2 divisors, whose sum is σ = 867640182. Its totient is φ = 867640180.

The previous prime is 867640159. The next prime is 867640217. The reversal of 867640181 is 181046768.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 821739556 + 45900625 = 28666^2 + 6775^2 .

It is a cyclic number.

It is not a de Polignac number, because 867640181 - 2¹⁴ = 867623797 is a prime.

It is a super-2 number, since 2×867640181² = 1505598967371425522, which contains 22 as substring.

It is a Sophie Germain 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 (867640141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433820090 + 433820091.

It is an arithmetic number, because the mean of its divisors is an integer number (433820091).

Almost surely, 2^867640181 is an apocalyptic number.

It is an amenable number.

867640181 is a deficient number, since it is larger than the sum of its proper divisors (1).

867640181 is an equidigital number, since it uses as much as digits as its factorization.

867640181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64512, while the sum is 41.

The square root of 867640181 is about 29455.7325660049. The cubic root of 867640181 is about 953.7763559310.

The spelling of 867640181 in words is "eight hundred sixty-seven million, six hundred forty thousand, one hundred eighty-one".