16121440109 has 2 divisors, whose sum is σ = 16121440110. Its totient is φ = 16121440108.

The previous prime is 16121440081. The next prime is 16121440133. The reversal of 16121440109 is 90104412161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15738455209 + 382984900 = 125453^2 + 19570^2 .

It is a cyclic number.

It is not a de Polignac number, because 16121440109 - 2⁸ = 16121439853 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16121440609) 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, 8060720054 + 8060720055.

It is an arithmetic number, because the mean of its divisors is an integer number (8060720055).

Almost surely, 2^16121440109 is an apocalyptic number.

It is an amenable number.

16121440109 is a deficient number, since it is larger than the sum of its proper divisors (1).

16121440109 is an equidigital number, since it uses as much as digits as its factorization.

16121440109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 29.

The spelling of 16121440109 in words is "sixteen billion, one hundred twenty-one million, four hundred forty thousand, one hundred nine".