211505513 has 2 divisors, whose sum is σ = 211505514. Its totient is φ = 211505512.

The previous prime is 211505507. The next prime is 211505531. The reversal of 211505513 is 315505112.

It is a happy number.

211505513 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

Together with next prime (211505531) 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., 117570649 + 93934864 = 10843^2 + 9692^2 .

It is a cyclic number.

It is not a de Polignac number, because 211505513 - 2²⁰ = 210456937 is a prime.

It is not a weakly prime, because it can be changed into another prime (211505543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105752756 + 105752757.

It is an arithmetic number, because the mean of its divisors is an integer number (105752757).

Almost surely, 2^211505513 is an apocalyptic number.

It is an amenable number.

211505513 is a deficient number, since it is larger than the sum of its proper divisors (1).

211505513 is an equidigital number, since it uses as much as digits as its factorization.

211505513 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 750, while the sum is 23.

The square root of 211505513 is about 14543.2291118582. The cubic root of 211505513 is about 595.8092352630.

The spelling of 211505513 in words is "two hundred eleven million, five hundred five thousand, five hundred thirteen".