243221403 has 4 divisors (see below), whose sum is σ = 324295208. Its totient is φ = 162147600.

The previous prime is 243221393. The next prime is 243221411. The reversal of 243221403 is 304122342.

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

It is not a de Polignac number, because 243221403 - 2⁵ = 243221371 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 243221403.

It is not an unprimeable number, because it can be changed into a prime (243221453) 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, 40536898 + ... + 40536903.

It is an arithmetic number, because the mean of its divisors is an integer number (81073802).

Almost surely, 2^243221403 is an apocalyptic number.

243221403 is a deficient number, since it is larger than the sum of its proper divisors (81073805).

243221403 is an equidigital number, since it uses as much as digits as its factorization.

243221403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81073804.

The product of its (nonzero) digits is 1152, while the sum is 21.

The square root of 243221403 is about 15595.5571558056. The cubic root of 243221403 is about 624.2146107019.

Adding to 243221403 its reverse (304122342), we get a palindrome (547343745).

The spelling of 243221403 in words is "two hundred forty-three million, two hundred twenty-one thousand, four hundred three".