20645251500473 has 2 divisors, whose sum is σ = 20645251500474. Its totient is φ = 20645251500472.

The previous prime is 20645251500413. The next prime is 20645251500479. The reversal of 20645251500473 is 37400515254602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20004982672249 + 640268828224 = 4472693^2 + 800168^2 .

It is a cyclic number.

It is not a de Polignac number, because 20645251500473 - 2¹⁰ = 20645251499449 is a prime.

It is not a weakly prime, because it can be changed into another prime (20645251500479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10322625750236 + 10322625750237.

It is an arithmetic number, because the mean of its divisors is an integer number (10322625750237).

Almost surely, 2^{20645251500473} is an apocalyptic number.

It is an amenable number.

20645251500473 is a deficient number, since it is larger than the sum of its proper divisors (1).

20645251500473 is an equidigital number, since it uses as much as digits as its factorization.

20645251500473 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008000, while the sum is 44.

The spelling of 20645251500473 in words is "twenty trillion, six hundred forty-five billion, two hundred fifty-one million, five hundred thousand, four hundred seventy-three".