20424811681 has 2 divisors, whose sum is σ = 20424811682. Its totient is φ = 20424811680.

The previous prime is 20424811663. The next prime is 20424811709. The reversal of 20424811681 is 18611842402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19944500625 + 480311056 = 141225^2 + 21916^2 .

It is a cyclic number.

It is not a de Polignac number, because 20424811681 - 2¹¹ = 20424809633 is a prime.

It is a super-2 number, since 2×20424811681² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20424811681.

It is not a weakly prime, because it can be changed into another prime (20424811651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10212405840 + 10212405841.

It is an arithmetic number, because the mean of its divisors is an integer number (10212405841).

Almost surely, 2^20424811681 is an apocalyptic number.

It is an amenable number.

20424811681 is a deficient number, since it is larger than the sum of its proper divisors (1).

20424811681 is an equidigital number, since it uses as much as digits as its factorization.

20424811681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24576, while the sum is 37.

The spelling of 20424811681 in words is "twenty billion, four hundred twenty-four million, eight hundred eleven thousand, six hundred eighty-one".