2181836369 has 2 divisors, whose sum is σ = 2181836370. Its totient is φ = 2181836368.

The previous prime is 2181836359. The next prime is 2181836407. The reversal of 2181836369 is 9636381812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2069158144 + 112678225 = 45488^2 + 10615^2 .

It is a cyclic number.

It is not a de Polignac number, because 2181836369 - 2⁸ = 2181836113 is a prime.

It is a super-2 number, since 2×2181836369² = 9520819882182208322, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is not a weakly prime, because it can be changed into another prime (2181836359) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1090918184 + 1090918185.

It is an arithmetic number, because the mean of its divisors is an integer number (1090918185).

Almost surely, 2^2181836369 is an apocalyptic number.

It is an amenable number.

2181836369 is a deficient number, since it is larger than the sum of its proper divisors (1).

2181836369 is an equidigital number, since it uses as much as digits as its factorization.

2181836369 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 373248, while the sum is 47.

The square root of 2181836369 is about 46710.1313314360. The cubic root of 2181836369 is about 1297.0022383228.

The spelling of 2181836369 in words is "two billion, one hundred eighty-one million, eight hundred thirty-six thousand, three hundred sixty-nine".