2640181 has 2 divisors, whose sum is σ = 2640182. Its totient is φ = 2640180.

The previous prime is 2640167. The next prime is 2640217. The reversal of 2640181 is 1810462.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2531281 + 108900 = 1591^2 + 330^2 .

It is a cyclic number.

It is not a de Polignac number, because 2640181 - 2⁹ = 2639669 is a prime.

It is a super-2 number, since 2×2640181² = 13941111425522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2640581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1320090 + 1320091.

It is an arithmetic number, because the mean of its divisors is an integer number (1320091).

2^2640181 is an apocalyptic number.

It is an amenable number.

2640181 is a deficient number, since it is larger than the sum of its proper divisors (1).

2640181 is an equidigital number, since it uses as much as digits as its factorization.

2640181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 2640181 is about 1624.8633788722. The cubic root of 2640181 is about 138.2116230801.

The spelling of 2640181 in words is "two million, six hundred forty thousand, one hundred eighty-one".