109921986721 has 2 divisors, whose sum is σ = 109921986722. Its totient is φ = 109921986720.

The previous prime is 109921986719. The next prime is 109921986743. The reversal of 109921986721 is 127689129901.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 89319690496 + 20602296225 = 298864^2 + 143535^2 .

It is an emirp because it is prime and its reverse (127689129901) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 109921986721 - 2¹ = 109921986719 is a prime.

Together with 109921986719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (109921986761) 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, 54960993360 + 54960993361.

It is an arithmetic number, because the mean of its divisors is an integer number (54960993361).

Almost surely, 2^109921986721 is an apocalyptic number.

It is an amenable number.

109921986721 is a deficient number, since it is larger than the sum of its proper divisors (1).

109921986721 is an equidigital number, since it uses as much as digits as its factorization.

109921986721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 979776, while the sum is 55.

The spelling of 109921986721 in words is "one hundred nine billion, nine hundred twenty-one million, nine hundred eighty-six thousand, seven hundred twenty-one".