20640000670643 has 2 divisors, whose sum is σ = 20640000670644. Its totient is φ = 20640000670642.

The previous prime is 20640000670607. The next prime is 20640000670697. The reversal of 20640000670643 is 34607600004602.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20640000670643 - 2¹⁸ = 20640000408499 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20640000670597 and 20640000670606.

It is not a weakly prime, because it can be changed into another prime (20640000670343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10320000335321 + 10320000335322.

It is an arithmetic number, because the mean of its divisors is an integer number (10320000335322).

Almost surely, 2^{20640000670643} is an apocalyptic number.

20640000670643 is a deficient number, since it is larger than the sum of its proper divisors (1).

20640000670643 is an equidigital number, since it uses as much as digits as its factorization.

20640000670643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 145152, while the sum is 38.

The spelling of 20640000670643 in words is "twenty trillion, six hundred forty billion, six hundred seventy thousand, six hundred forty-three".