2161018213 has 2 divisors, whose sum is σ = 2161018214. Its totient is φ = 2161018212.

The previous prime is 2161018207. The next prime is 2161018231. The reversal of 2161018213 is 3128101612.

Together with next prime (2161018231) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1784386564 + 376631649 = 42242^2 + 19407^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2161018213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2161018813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1080509106 + 1080509107.

It is an arithmetic number, because the mean of its divisors is an integer number (1080509107).

Almost surely, 2^2161018213 is an apocalyptic number.

It is an amenable number.

2161018213 is a deficient number, since it is larger than the sum of its proper divisors (1).

2161018213 is an equidigital number, since it uses as much as digits as its factorization.

2161018213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 2161018213 is about 46486.7530916066. The cubic root of 2161018213 is about 1292.8639000195.

Adding to 2161018213 its reverse (3128101612), we get a palindrome (5289119825).

The spelling of 2161018213 in words is "two billion, one hundred sixty-one million, eighteen thousand, two hundred thirteen".