211856797 has 2 divisors, whose sum is σ = 211856798. Its totient is φ = 211856796.

The previous prime is 211856779. The next prime is 211856809. The reversal of 211856797 is 797658112.

It is a happy number.

211856797 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

Together with previous prime (211856779) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 128572921 + 83283876 = 11339^2 + 9126^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211856797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211856767) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105928398 + 105928399.

It is an arithmetic number, because the mean of its divisors is an integer number (105928399).

Almost surely, 2^211856797 is an apocalyptic number.

It is an amenable number.

211856797 is a deficient number, since it is larger than the sum of its proper divisors (1).

211856797 is an equidigital number, since it uses as much as digits as its factorization.

211856797 is an evil number, because the sum of its binary digits is even.

The product of its digits is 211680, while the sum is 46.

The square root of 211856797 is about 14555.3013366265. The cubic root of 211856797 is about 596.1389074979.

The spelling of 211856797 in words is "two hundred eleven million, eight hundred fifty-six thousand, seven hundred ninety-seven".