20638768794389 has 16 divisors (see below), whose sum is σ = 21013093570560. Its totient is φ = 20267866785600.

The previous prime is 20638768794353. The next prime is 20638768794431. The reversal of 20638768794389 is 98349786783602.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20638768794389 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20638768794289) 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 in 15 ways as a sum of consecutive naturals, for example, 46121282 + ... + 46566620.

It is an arithmetic number, because the mean of its divisors is an integer number (1313318348160).

Almost surely, 2^{20638768794389} is an apocalyptic number.

It is an amenable number.

20638768794389 is a deficient number, since it is larger than the sum of its proper divisors (374324776171).

20638768794389 is a wasteful number, since it uses less digits than its factorization.

20638768794389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 449180.

The product of its (nonzero) digits is 5267275776, while the sum is 80.

The spelling of 20638768794389 in words is "twenty trillion, six hundred thirty-eight billion, seven hundred sixty-eight million, seven hundred ninety-four thousand, three hundred eighty-nine".