201231023309 has 2 divisors, whose sum is σ = 201231023310. Its totient is φ = 201231023308.

The previous prime is 201231023281. The next prime is 201231023407. The reversal of 201231023309 is 903320132102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 196295960809 + 4935062500 = 443053^2 + 70250^2 .

It is a cyclic number.

It is not a de Polignac number, because 201231023309 - 2¹⁶ = 201230957773 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201231023009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100615511654 + 100615511655.

It is an arithmetic number, because the mean of its divisors is an integer number (100615511655).

Almost surely, 2^201231023309 is an apocalyptic number.

It is an amenable number.

201231023309 is a deficient number, since it is larger than the sum of its proper divisors (1).

201231023309 is an equidigital number, since it uses as much as digits as its factorization.

201231023309 is an odious number, because the sum of its binary digits is odd.

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

The spelling of 201231023309 in words is "two hundred one billion, two hundred thirty-one million, twenty-three thousand, three hundred nine".