203123204321 has 4 divisors (see below), whose sum is σ = 208613020692. Its totient is φ = 197633387952.

The previous prime is 203123204309. The next prime is 203123204329. The reversal of 203123204321 is 123402321302.

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

It can be written as a sum of positive squares in 2 ways, for example, as 193894912225 + 9228292096 = 440335^2 + 96064^2 .

It is a cyclic number.

It is not a de Polignac number, because 203123204321 - 2⁶ = 203123204257 is a prime.

It is a super-2 number, since 2×203123204321² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (203123204329) 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 3 ways as a sum of consecutive naturals, for example, 2744908130 + ... + 2744908203.

It is an arithmetic number, because the mean of its divisors is an integer number (52153255173).

Almost surely, 2^203123204321 is an apocalyptic number.

It is an amenable number.

203123204321 is a deficient number, since it is larger than the sum of its proper divisors (5489816371).

203123204321 is an equidigital number, since it uses as much as digits as its factorization.

203123204321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5489816370.

The product of its (nonzero) digits is 1728, while the sum is 23.

Adding to 203123204321 its reverse (123402321302), we get a palindrome (326525525623).

The spelling of 203123204321 in words is "two hundred three billion, one hundred twenty-three million, two hundred four thousand, three hundred twenty-one".