221312403 has 24 divisors (see below), whose sum is σ = 346801728. Its totient is φ = 135188352.

The previous prime is 221312393. The next prime is 221312411. The reversal of 221312403 is 304213122.

It is not a de Polignac number, because 221312403 - 2¹⁰ = 221311379 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221312423) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9126 + ... + 22932.

It is an arithmetic number, because the mean of its divisors is an integer number (14450072).

Almost surely, 2^221312403 is an apocalyptic number.

221312403 is a deficient number, since it is larger than the sum of its proper divisors (125489325).

221312403 is a wasteful number, since it uses less digits than its factorization.

221312403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13963 (or 13960 counting only the distinct ones).

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

The square root of 221312403 is about 14876.5722866526. The cubic root of 221312403 is about 604.8791079623.

Adding to 221312403 its reverse (304213122), we get a palindrome (525525525).

The spelling of 221312403 in words is "two hundred twenty-one million, three hundred twelve thousand, four hundred three".