2111021909 has 2 divisors, whose sum is σ = 2111021910. Its totient is φ = 2111021908.

The previous prime is 2111021897. The next prime is 2111021933. The reversal of 2111021909 is 9091201112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1881650884 + 229371025 = 43378^2 + 15145^2 .

It is a cyclic number.

It is not a de Polignac number, because 2111021909 - 2⁴ = 2111021893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2111021009) 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, 1055510954 + 1055510955.

It is an arithmetic number, because the mean of its divisors is an integer number (1055510955).

Almost surely, 2^2111021909 is an apocalyptic number.

It is an amenable number.

2111021909 is a deficient number, since it is larger than the sum of its proper divisors (1).

2111021909 is an equidigital number, since it uses as much as digits as its factorization.

2111021909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324, while the sum is 26.

The square root of 2111021909 is about 45945.8584531838. The cubic root of 2111021909 is about 1282.8156420435.

The spelling of 2111021909 in words is "two billion, one hundred eleven million, twenty-one thousand, nine hundred nine".