491149181 has 2 divisors, whose sum is σ = 491149182. Its totient is φ = 491149180.

The previous prime is 491149157. The next prime is 491149187. The reversal of 491149181 is 181941194.

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., 449016100 + 42133081 = 21190^2 + 6491^2 .

It is a cyclic number.

It is not a de Polignac number, because 491149181 - 2²² = 486954877 is a prime.

It is a super-2 number, since 2×491149181² = 482455035993941522, 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 (491149187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245574590 + 245574591.

It is an arithmetic number, because the mean of its divisors is an integer number (245574591).

Almost surely, 2^491149181 is an apocalyptic number.

It is an amenable number.

491149181 is a deficient number, since it is larger than the sum of its proper divisors (1).

491149181 is an equidigital number, since it uses as much as digits as its factorization.

491149181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 38.

The square root of 491149181 is about 22161.8857726503. The cubic root of 491149181 is about 788.9893506841.

The spelling of 491149181 in words is "four hundred ninety-one million, one hundred forty-nine thousand, one hundred eighty-one".