5181581 has 2 divisors, whose sum is σ = 5181582. Its totient is φ = 5181580.

The previous prime is 5181569. The next prime is 5181587. The reversal of 5181581 is 1851815.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3822025 + 1359556 = 1955^2 + 1166^2 .

It is a cyclic number.

It is not a de Polignac number, because 5181581 - 2¹⁸ = 4919437 is a prime.

It is a super-2 number, since 2×5181581² = 53697563319122, 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 (5181587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2590790 + 2590791.

It is an arithmetic number, because the mean of its divisors is an integer number (2590791).

Almost surely, 2^5181581 is an apocalyptic number.

It is an amenable number.

5181581 is a deficient number, since it is larger than the sum of its proper divisors (1).

5181581 is an equidigital number, since it uses as much as digits as its factorization.

5181581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1600, while the sum is 29.

The square root of 5181581 is about 2276.3086346100. The cubic root of 5181581 is about 173.0430244823.

The spelling of 5181581 in words is "five million, one hundred eighty-one thousand, five hundred eighty-one".