200123126509 has 2 divisors, whose sum is σ = 200123126510. Its totient is φ = 200123126508.

The previous prime is 200123126473. The next prime is 200123126519. The reversal of 200123126509 is 905621321002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 175061070409 + 25062056100 = 418403^2 + 158310^2 .

It is a cyclic number.

It is not a de Polignac number, because 200123126509 - 2¹⁹ = 200122602221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (200123126519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100061563254 + 100061563255.

It is an arithmetic number, because the mean of its divisors is an integer number (100061563255).

Almost surely, 2^200123126509 is an apocalyptic number.

It is an amenable number.

200123126509 is a deficient number, since it is larger than the sum of its proper divisors (1).

200123126509 is an equidigital number, since it uses as much as digits as its factorization.

200123126509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 31.

The spelling of 200123126509 in words is "two hundred billion, one hundred twenty-three million, one hundred twenty-six thousand, five hundred nine".