20643914729 has 2 divisors, whose sum is σ = 20643914730. Its totient is φ = 20643914728.

The previous prime is 20643914699. The next prime is 20643914747. The reversal of 20643914729 is 92741934602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12157267600 + 8486647129 = 110260^2 + 92123^2 .

It is a cyclic number.

It is not a de Polignac number, because 20643914729 - 2¹² = 20643910633 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (20643917729) 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, 10321957364 + 10321957365.

It is an arithmetic number, because the mean of its divisors is an integer number (10321957365).

Almost surely, 2^20643914729 is an apocalyptic number.

It is an amenable number.

20643914729 is a deficient number, since it is larger than the sum of its proper divisors (1).

20643914729 is an equidigital number, since it uses as much as digits as its factorization.

20643914729 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 653184, while the sum is 47.

The spelling of 20643914729 in words is "twenty billion, six hundred forty-three million, nine hundred fourteen thousand, seven hundred twenty-nine".