203123312009 has 2 divisors, whose sum is σ = 203123312010. Its totient is φ = 203123312008.

The previous prime is 203123312003. The next prime is 203123312033. The reversal of 203123312009 is 900213321302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 195919546384 + 7203765625 = 442628^2 + 84875^2 .

It is a cyclic number.

It is not a de Polignac number, because 203123312009 - 2³² = 198828344713 is a prime.

It is not a weakly prime, because it can be changed into another prime (203123312003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101561656004 + 101561656005.

It is an arithmetic number, because the mean of its divisors is an integer number (101561656005).

Almost surely, 2^203123312009 is an apocalyptic number.

It is an amenable number.

203123312009 is a deficient number, since it is larger than the sum of its proper divisors (1).

203123312009 is an equidigital number, since it uses as much as digits as its factorization.

203123312009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 26.

The spelling of 203123312009 in words is "two hundred three billion, one hundred twenty-three million, three hundred twelve thousand, nine".