211112509 has 2 divisors, whose sum is σ = 211112510. Its totient is φ = 211112508.

The previous prime is 211112507. The next prime is 211112513. The reversal of 211112509 is 905211112.

211112509 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 179640409 + 31472100 = 13403^2 + 5610^2 .

It is a cyclic number.

It is not a de Polignac number, because 211112509 - 2¹ = 211112507 is a prime.

Together with 211112507, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 211112509.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211112507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105556254 + 105556255.

It is an arithmetic number, because the mean of its divisors is an integer number (105556255).

Almost surely, 2^211112509 is an apocalyptic number.

It is an amenable number.

211112509 is a deficient number, since it is larger than the sum of its proper divisors (1).

211112509 is an equidigital number, since it uses as much as digits as its factorization.

211112509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 180, while the sum is 22.

The square root of 211112509 is about 14529.7112497117. The cubic root of 211112509 is about 595.4399768145.

The spelling of 211112509 in words is "two hundred eleven million, one hundred twelve thousand, five hundred nine".