2188181 has 2 divisors, whose sum is σ = 2188182. Its totient is φ = 2188180.

The previous prime is 2188171. The next prime is 2188213. The reversal of 2188181 is 1818812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1562500 + 625681 = 1250^2 + 791^2 .

It is a cyclic number.

It is not a de Polignac number, because 2188181 - 2⁶ = 2188117 is a prime.

It is a super-2 number, since 2×2188181² = 9576272177522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2188111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1094090 + 1094091.

It is an arithmetic number, because the mean of its divisors is an integer number (1094091).

2^2188181 is an apocalyptic number.

It is an amenable number.

2188181 is a deficient number, since it is larger than the sum of its proper divisors (1).

2188181 is an equidigital number, since it uses as much as digits as its factorization.

2188181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1024, while the sum is 29.

The square root of 2188181 is about 1479.2501478790. The cubic root of 2188181 is about 129.8258219619.

The spelling of 2188181 in words is "two million, one hundred eighty-eight thousand, one hundred eighty-one".