211751993 has 2 divisors, whose sum is σ = 211751994. Its totient is φ = 211751992.

The previous prime is 211751989. The next prime is 211752001. The reversal of 211751993 is 399157112.

211751993 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., 188980009 + 22771984 = 13747^2 + 4772^2 .

It is a cyclic number.

It is not a de Polignac number, because 211751993 - 2² = 211751989 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (211751893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105875996 + 105875997.

It is an arithmetic number, because the mean of its divisors is an integer number (105875997).

Almost surely, 2^211751993 is an apocalyptic number.

It is an amenable number.

211751993 is a deficient number, since it is larger than the sum of its proper divisors (1).

211751993 is an equidigital number, since it uses as much as digits as its factorization.

211751993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17010, while the sum is 38.

The square root of 211751993 is about 14551.7006909845. The cubic root of 211751993 is about 596.0405894387.

The spelling of 211751993 in words is "two hundred eleven million, seven hundred fifty-one thousand, nine hundred ninety-three".