1201686181 has 2 divisors, whose sum is σ = 1201686182. Its totient is φ = 1201686180.

The previous prime is 1201686163. The next prime is 1201686193. The reversal of 1201686181 is 1816861021.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1063412100 + 138274081 = 32610^2 + 11759^2 .

It is a cyclic number.

It is not a de Polignac number, because 1201686181 - 2⁷ = 1201686053 is a prime.

It is a super-2 number, since 2×1201686181² = 2888099355212729522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1201686131) 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, 600843090 + 600843091.

It is an arithmetic number, because the mean of its divisors is an integer number (600843091).

Almost surely, 2^1201686181 is an apocalyptic number.

It is an amenable number.

1201686181 is a deficient number, since it is larger than the sum of its proper divisors (1).

1201686181 is an equidigital number, since it uses as much as digits as its factorization.

1201686181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4608, while the sum is 34.

The square root of 1201686181 is about 34665.3455341210. The cubic root of 1201686181 is about 1063.1560680930.

The spelling of 1201686181 in words is "one billion, two hundred one million, six hundred eighty-six thousand, one hundred eighty-one".