20424811709 has 2 divisors, whose sum is σ = 20424811710. Its totient is φ = 20424811708.

The previous prime is 20424811681. The next prime is 20424811711. The reversal of 20424811709 is 90711842402.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12328771225 + 8096040484 = 111035^2 + 89978^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20424811709 is a prime.

Together with 20424811711, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20424811609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10212405854 + 10212405855.

It is an arithmetic number, because the mean of its divisors is an integer number (10212405855).

Almost surely, 2^20424811709 is an apocalyptic number.

It is an amenable number.

20424811709 is a deficient number, since it is larger than the sum of its proper divisors (1).

20424811709 is an equidigital number, since it uses as much as digits as its factorization.

20424811709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32256, while the sum is 38.

The spelling of 20424811709 in words is "twenty billion, four hundred twenty-four million, eight hundred eleven thousand, seven hundred nine".