211223121 has 16 divisors (see below), whose sum is σ = 290519424. Its totient is φ = 136404864.

The previous prime is 211223087. The next prime is 211223137. The reversal of 211223121 is 121322112.

It is not a de Polignac number, because 211223121 - 2¹⁰ = 211222097 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 211223121.

It is not an unprimeable number, because it can be changed into a prime (211223321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21780 + ... + 29946.

It is an arithmetic number, because the mean of its divisors is an integer number (18157464).

Almost surely, 2^211223121 is an apocalyptic number.

It is an amenable number.

211223121 is a deficient number, since it is larger than the sum of its proper divisors (79296303).

211223121 is a wasteful number, since it uses less digits than its factorization.

211223121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8440.

The product of its digits is 48, while the sum is 15.

The square root of 211223121 is about 14533.5171586234. The cubic root of 211223121 is about 595.5439518742.

Adding to 211223121 its reverse (121322112), we get a palindrome (332545233).

The spelling of 211223121 in words is "two hundred eleven million, two hundred twenty-three thousand, one hundred twenty-one".