109919251721 has 2 divisors, whose sum is σ = 109919251722. Its totient is φ = 109919251720.

The previous prime is 109919251613. The next prime is 109919251817. The reversal of 109919251721 is 127152919901.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 92500531321 + 17418720400 = 304139^2 + 131980^2 .

It is a cyclic number.

It is not a de Polignac number, because 109919251721 - 2¹⁴ = 109919235337 is a prime.

It is a super-2 number, since 2×109919251721² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (109919259721) 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, 54959625860 + 54959625861.

It is an arithmetic number, because the mean of its divisors is an integer number (54959625861).

Almost surely, 2^109919251721 is an apocalyptic number.

It is an amenable number.

109919251721 is a deficient number, since it is larger than the sum of its proper divisors (1).

109919251721 is an equidigital number, since it uses as much as digits as its factorization.

109919251721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 102060, while the sum is 47.

The spelling of 109919251721 in words is "one hundred nine billion, nine hundred nineteen million, two hundred fifty-one thousand, seven hundred twenty-one".