101010991909 has 2 divisors, whose sum is σ = 101010991910. Its totient is φ = 101010991908.

The previous prime is 101010991891. The next prime is 101010991919. The reversal of 101010991909 is 909199010101.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78345689409 + 22665302500 = 279903^2 + 150550^2 .

It is a cyclic number.

It is not a de Polignac number, because 101010991909 - 2¹⁷ = 101010860837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (101010991919) 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, 50505495954 + 50505495955.

It is an arithmetic number, because the mean of its divisors is an integer number (50505495955).

Almost surely, 2^101010991909 is an apocalyptic number.

It is an amenable number.

101010991909 is a deficient number, since it is larger than the sum of its proper divisors (1).

101010991909 is an equidigital number, since it uses as much as digits as its factorization.

101010991909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6561, while the sum is 40.

The spelling of 101010991909 in words is "one hundred one billion, ten million, nine hundred ninety-one thousand, nine hundred nine".