2181329 has 2 divisors, whose sum is σ = 2181330. Its totient is φ = 2181328.

The previous prime is 2181271. The next prime is 2181331. The reversal of 2181329 is 9231812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2131600 + 49729 = 1460^2 + 223^2 .

It is a cyclic number.

It is not a de Polignac number, because 2181329 - 2⁸ = 2181073 is a prime.

Together with 2181331, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 2181298 and 2181307.

It is not a weakly prime, because it can be changed into another prime (2181349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1090664 + 1090665.

It is an arithmetic number, because the mean of its divisors is an integer number (1090665).

2^2181329 is an apocalyptic number.

It is an amenable number.

2181329 is a deficient number, since it is larger than the sum of its proper divisors (1).

2181329 is an equidigital number, since it uses as much as digits as its factorization.

2181329 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 26.

The square root of 2181329 is about 1476.9322936411. The cubic root of 2181329 is about 129.6901694617.

The spelling of 2181329 in words is "two million, one hundred eighty-one thousand, three hundred twenty-nine".