211312391 has 2 divisors, whose sum is σ = 211312392. Its totient is φ = 211312390.

The previous prime is 211312351. The next prime is 211312393. The reversal of 211312391 is 193213112.

211312391 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 211312391 - 2⁶ = 211312327 is a prime.

Together with 211312393, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211312393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105656195 + 105656196.

It is an arithmetic number, because the mean of its divisors is an integer number (105656196).

Almost surely, 2^211312391 is an apocalyptic number.

211312391 is a deficient number, since it is larger than the sum of its proper divisors (1).

211312391 is an equidigital number, since it uses as much as digits as its factorization.

211312391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 324, while the sum is 23.

The square root of 211312391 is about 14536.5880109467. The cubic root of 211312391 is about 595.6278390301.

The spelling of 211312391 in words is "two hundred eleven million, three hundred twelve thousand, three hundred ninety-one".