211401221 has 4 divisors (see below), whose sum is σ = 211578444. Its totient is φ = 211224000.

The previous prime is 211401209. The next prime is 211401227. The reversal of 211401221 is 122104112.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 65836996 + 145564225 = 8114^2 + 12065^2 .

It is a cyclic number.

It is not a de Polignac number, because 211401221 - 2¹⁴ = 211384837 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211401196 and 211401205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211401227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 86810 + ... + 89211.

It is an arithmetic number, because the mean of its divisors is an integer number (52894611).

Almost surely, 2^211401221 is an apocalyptic number.

It is an amenable number.

211401221 is a deficient number, since it is larger than the sum of its proper divisors (177223).

211401221 is a wasteful number, since it uses less digits than its factorization.

211401221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177222.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 211401221 is about 14539.6430836524. The cubic root of 211401221 is about 595.7112892694.

Adding to 211401221 its reverse (122104112), we get a palindrome (333505333).

The spelling of 211401221 in words is "two hundred eleven million, four hundred one thousand, two hundred twenty-one".