123133691909 has 2 divisors, whose sum is σ = 123133691910. Its totient is φ = 123133691908.

The previous prime is 123133691897. The next prime is 123133691959. The reversal of 123133691909 is 909196331321.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 119372323009 + 3761368900 = 345503^2 + 61330^2 .

It is a cyclic number.

It is not a de Polignac number, because 123133691909 - 2²⁴ = 123116914693 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123133691959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61566845954 + 61566845955.

It is an arithmetic number, because the mean of its divisors is an integer number (61566845955).

Almost surely, 2^123133691909 is an apocalyptic number.

It is an amenable number.

123133691909 is a deficient number, since it is larger than the sum of its proper divisors (1).

123133691909 is an equidigital number, since it uses as much as digits as its factorization.

123133691909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 236196, while the sum is 47.

The spelling of 123133691909 in words is "one hundred twenty-three billion, one hundred thirty-three million, six hundred ninety-one thousand, nine hundred nine".