221210123 has 4 divisors (see below), whose sum is σ = 223695720. Its totient is φ = 218724528.

The previous prime is 221210111. The next prime is 221210131. The reversal of 221210123 is 321012122.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 221210123 - 2¹⁶ = 221144587 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221210098 and 221210107.

It is not an unprimeable number, because it can be changed into a prime (221210323) 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, 1242665 + ... + 1242842.

It is an arithmetic number, because the mean of its divisors is an integer number (55923930).

Almost surely, 2^221210123 is an apocalyptic number.

221210123 is a deficient number, since it is larger than the sum of its proper divisors (2485597).

221210123 is an equidigital number, since it uses as much as digits as its factorization.

221210123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2485596.

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

The square root of 221210123 is about 14873.1342695479. The cubic root of 221210123 is about 604.7859115464.

Adding to 221210123 its reverse (321012122), we get a palindrome (542222245).

The spelling of 221210123 in words is "two hundred twenty-one million, two hundred ten thousand, one hundred twenty-three".