221403123 has 12 divisors (see below), whose sum is σ = 321952800. Its totient is φ = 146610576.

The previous prime is 221403113. The next prime is 221403137. The reversal of 221403123 is 321304122.

It is not a de Polignac number, because 221403123 - 2⁶ = 221403059 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221403096 and 221403105.

It is not an unprimeable number, because it can be changed into a prime (221403103) 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 in 11 ways as a sum of consecutive naturals, for example, 81211 + ... + 83892.

It is an arithmetic number, because the mean of its divisors is an integer number (26829400).

Almost surely, 2^221403123 is an apocalyptic number.

221403123 is a deficient number, since it is larger than the sum of its proper divisors (100549677).

221403123 is a wasteful number, since it uses less digits than its factorization.

221403123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165258 (or 165255 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 221403123 is about 14879.6210637234. The cubic root of 221403123 is about 604.9617470065.

Adding to 221403123 its reverse (321304122), we get a palindrome (542707245).

Subtracting 221403123 from its reverse (321304122), we obtain a palindrome (99900999).

The spelling of 221403123 in words is "two hundred twenty-one million, four hundred three thousand, one hundred twenty-three".