211220123 has 2 divisors, whose sum is σ = 211220124. Its totient is φ = 211220122.

The previous prime is 211220117. The next prime is 211220153. The reversal of 211220123 is 321022112.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 211220123 - 2¹⁴ = 211203739 is a prime.

It is a super-2 number, since 2×211220123² = 89227880720270258, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 211220098 and 211220107.

It is not a weakly prime, because it can be changed into another prime (211220153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105610061 + 105610062.

It is an arithmetic number, because the mean of its divisors is an integer number (105610062).

Almost surely, 2^211220123 is an apocalyptic number.

211220123 is a deficient number, since it is larger than the sum of its proper divisors (1).

211220123 is an equidigital number, since it uses as much as digits as its factorization.

211220123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 211220123 is about 14533.4140173601. The cubic root of 211220123 is about 595.5411342388.

Adding to 211220123 its reverse (321022112), we get a palindrome (532242235).

The spelling of 211220123 in words is "two hundred eleven million, two hundred twenty thousand, one hundred twenty-three".