211440121 has 4 divisors (see below), whose sum is σ = 211560100. Its totient is φ = 211320144.

The previous prime is 211440109. The next prime is 211440133. The reversal of 211440121 is 121044112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (211440109) and next prime (211440133).

It can be written as a sum of positive squares in 2 ways, for example, as 201327721 + 10112400 = 14189^2 + 3180^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211440121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211440095 and 211440104.

It is not an unprimeable number, because it can be changed into a prime (211440521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57306 + ... + 60883.

It is an arithmetic number, because the mean of its divisors is an integer number (52890025).

Almost surely, 2^211440121 is an apocalyptic number.

It is an amenable number.

211440121 is a deficient number, since it is larger than the sum of its proper divisors (119979).

211440121 is a wasteful number, since it uses less digits than its factorization.

211440121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119978.

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 211440121 is about 14540.9807440901. The cubic root of 211440121 is about 595.7478260308.

Adding to 211440121 its reverse (121044112), we get a palindrome (332484233).

The spelling of 211440121 in words is "two hundred eleven million, four hundred forty thousand, one hundred twenty-one".