2509181 has 2 divisors, whose sum is σ = 2509182. Its totient is φ = 2509180.

The previous prime is 2509163. The next prime is 2509207. The reversal of 2509181 is 1819052.

It is a happy number.

It is an a-pointer prime, because the next prime (2509207) can be obtained adding 2509181 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2353156 + 156025 = 1534^2 + 395^2 .

It is a cyclic number.

It is not a de Polignac number, because 2509181 - 2¹⁴ = 2492797 is a prime.

It is a super-3 number, since 3×2509181³ = 47393330113742930223, which contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 2509181.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2509141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1254590 + 1254591.

It is an arithmetic number, because the mean of its divisors is an integer number (1254591).

2^2509181 is an apocalyptic number.

It is an amenable number.

2509181 is a deficient number, since it is larger than the sum of its proper divisors (1).

2509181 is an equidigital number, since it uses as much as digits as its factorization.

2509181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 720, while the sum is 26.

The square root of 2509181 is about 1584.0394565793. The cubic root of 2509181 is about 135.8868183199.

The spelling of 2509181 in words is "two million, five hundred nine thousand, one hundred eighty-one".