2181539 has 2 divisors, whose sum is σ = 2181540. Its totient is φ = 2181538.

The previous prime is 2181503. The next prime is 2181541. The reversal of 2181539 is 9351812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2181539 - 2¹² = 2177443 is a prime.

It is a super-2 number, since 2×2181539² = 9518224817042, which contains 22 as substring.

Together with 2181541, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2181139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1090769 + 1090770.

It is an arithmetic number, because the mean of its divisors is an integer number (1090770).

2^2181539 is an apocalyptic number.

2181539 is a deficient number, since it is larger than the sum of its proper divisors (1).

2181539 is an equidigital number, since it uses as much as digits as its factorization.

2181539 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2160, while the sum is 29.

The square root of 2181539 is about 1477.0033852365. The cubic root of 2181539 is about 129.6943311542.

The spelling of 2181539 in words is "two million, one hundred eighty-one thousand, five hundred thirty-nine".