211811121 has 24 divisors (see below), whose sum is σ = 312624000. Its totient is φ = 138150432.

The previous prime is 211811111. The next prime is 211811123. The reversal of 211811121 is 121118112.

It is not a de Polignac number, because 211811121 - 2⁶ = 211811057 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 211811094 and 211811103.

It is not an unprimeable number, because it can be changed into a prime (211811123) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 126075 + ... + 127743.

It is an arithmetic number, because the mean of its divisors is an integer number (13026000).

Almost surely, 2^211811121 is an apocalyptic number.

It is an amenable number.

211811121 is a deficient number, since it is larger than the sum of its proper divisors (100812879).

211811121 is a wasteful number, since it uses less digits than its factorization.

211811121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1973 (or 1970 counting only the distinct ones).

The product of its digits is 32, while the sum is 18.

The square root of 211811121 is about 14553.7322017412. The cubic root of 211811121 is about 596.0960622077.

Adding to 211811121 its reverse (121118112), we get a palindrome (332929233).

The spelling of 211811121 in words is "two hundred eleven million, eight hundred eleven thousand, one hundred twenty-one".