2181215111 has 2 divisors, whose sum is σ = 2181215112. Its totient is φ = 2181215110.

The previous prime is 2181215093. The next prime is 2181215137. The reversal of 2181215111 is 1115121812.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2181215111 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2181215711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1090607555 + 1090607556.

It is an arithmetic number, because the mean of its divisors is an integer number (1090607556).

Almost surely, 2^2181215111 is an apocalyptic number.

2181215111 is a deficient number, since it is larger than the sum of its proper divisors (1).

2181215111 is an equidigital number, since it uses as much as digits as its factorization.

2181215111 is an evil number, because the sum of its binary digits is even.

The product of its digits is 160, while the sum is 23.

The square root of 2181215111 is about 46703.4807161094. The cubic root of 2181215111 is about 1296.8791234521.

Adding to 2181215111 its reverse (1115121812), we get a palindrome (3296336923).

The spelling of 2181215111 in words is "two billion, one hundred eighty-one million, two hundred fifteen thousand, one hundred eleven".