211806423 has 6 divisors (see below), whose sum is σ = 305942624. Its totient is φ = 141204276.

The previous prime is 211806421. The next prime is 211806431. The reversal of 211806423 is 324608112.

211806423 is a `hidden beast` number, since 2 + 1 + 18 + 0 + 642 + 3 = 666.

It is not a de Polignac number, because 211806423 - 2¹ = 211806421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211806421) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11767015 + ... + 11767032.

Almost surely, 2^211806423 is an apocalyptic number.

211806423 is a deficient number, since it is larger than the sum of its proper divisors (94136201).

211806423 is a wasteful number, since it uses less digits than its factorization.

211806423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23534053 (or 23534050 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 211806423 is about 14553.5707989483. The cubic root of 211806423 is about 596.0916550107.

The spelling of 211806423 in words is "two hundred eleven million, eight hundred six thousand, four hundred twenty-three".