21000116805727 has 2 divisors, whose sum is σ = 21000116805728. Its totient is φ = 21000116805726.

The previous prime is 21000116805721. The next prime is 21000116805761. The reversal of 21000116805727 is 72750861100012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21000116805727 - 2³ = 21000116805719 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21000116805727.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21000116805721) 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, 10500058402863 + 10500058402864.

It is an arithmetic number, because the mean of its divisors is an integer number (10500058402864).

Almost surely, 2^{21000116805727} is an apocalyptic number.

21000116805727 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000116805727 is an equidigital number, since it uses as much as digits as its factorization.

21000116805727 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 47040, while the sum is 40.

Adding to 21000116805727 its reverse (72750861100012), we get a palindrome (93750977905739).

The spelling of 21000116805727 in words is "twenty-one trillion, one hundred sixteen million, eight hundred five thousand, seven hundred twenty-seven".