681181181 has 2 divisors, whose sum is σ = 681181182. Its totient is φ = 681181180.

The previous prime is 681181159. The next prime is 681181183. The reversal of 681181181 is 181181186.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 382202500 + 298978681 = 19550^2 + 17291^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-681181181 is a prime.

It is a super-2 number, since 2×681181181² = 928015602697109522, which contains 22 as substring.

Together with 681181183, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (681181183) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340590590 + 340590591.

It is an arithmetic number, because the mean of its divisors is an integer number (340590591).

Almost surely, 2^681181181 is an apocalyptic number.

It is an amenable number.

681181181 is a deficient number, since it is larger than the sum of its proper divisors (1).

681181181 is an equidigital number, since it uses as much as digits as its factorization.

681181181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3072, while the sum is 35.

The square root of 681181181 is about 26099.4479060382. The cubic root of 681181181 is about 879.8748018341.

The spelling of 681181181 in words is "six hundred eighty-one million, one hundred eighty-one thousand, one hundred eighty-one".