20243781709 has 2 divisors, whose sum is σ = 20243781710. Its totient is φ = 20243781708.

The previous prime is 20243781689. The next prime is 20243781721. The reversal of 20243781709 is 90718734202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16150597225 + 4093184484 = 127085^2 + 63978^2 .

It is a cyclic number.

It is not a de Polignac number, because 20243781709 - 2²¹ = 20241684557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20243781739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10121890854 + 10121890855.

It is an arithmetic number, because the mean of its divisors is an integer number (10121890855).

Almost surely, 2^20243781709 is an apocalyptic number.

It is an amenable number.

20243781709 is a deficient number, since it is larger than the sum of its proper divisors (1).

20243781709 is an equidigital number, since it uses as much as digits as its factorization.

20243781709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 169344, while the sum is 43.

The spelling of 20243781709 in words is "twenty billion, two hundred forty-three million, seven hundred eighty-one thousand, seven hundred nine".