2111299781 has 2 divisors, whose sum is σ = 2111299782. Its totient is φ = 2111299780.

The previous prime is 2111299777. The next prime is 2111299787. The reversal of 2111299781 is 1879921112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1916250625 + 195049156 = 43775^2 + 13966^2 .

It is a cyclic number.

It is not a de Polignac number, because 2111299781 - 2² = 2111299777 is a prime.

It is a super-2 number, since 2×2111299781² = 8915173530501295922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2111299787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1055649890 + 1055649891.

It is an arithmetic number, because the mean of its divisors is an integer number (1055649891).

Almost surely, 2^2111299781 is an apocalyptic number.

It is an amenable number.

2111299781 is a deficient number, since it is larger than the sum of its proper divisors (1).

2111299781 is an equidigital number, since it uses as much as digits as its factorization.

2111299781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18144, while the sum is 41.

The square root of 2111299781 is about 45948.8822606165. The cubic root of 2111299781 is about 1282.8719248809.

The spelling of 2111299781 in words is "two billion, one hundred eleven million, two hundred ninety-nine thousand, seven hundred eighty-one".