20645473443677 has 2 divisors, whose sum is σ = 20645473443678. Its totient is φ = 20645473443676.

The previous prime is 20645473443653. The next prime is 20645473443689. The reversal of 20645473443677 is 77634437454602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20424804623161 + 220668820516 = 4519381^2 + 469754^2 .

It is a cyclic number.

It is not a de Polignac number, because 20645473443677 - 2¹⁰ = 20645473442653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20645473443697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10322736721838 + 10322736721839.

It is an arithmetic number, because the mean of its divisors is an integer number (10322736721839).

Almost surely, 2^{20645473443677} is an apocalyptic number.

It is an amenable number.

20645473443677 is a deficient number, since it is larger than the sum of its proper divisors (1).

20645473443677 is an equidigital number, since it uses as much as digits as its factorization.

20645473443677 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 284497920, while the sum is 62.

The spelling of 20645473443677 in words is "twenty trillion, six hundred forty-five billion, four hundred seventy-three million, four hundred forty-three thousand, six hundred seventy-seven".