9181909091909 has 4 divisors (see below), whose sum is σ = 9272819083020. Its totient is φ = 9090999100800.

The previous prime is 9181909091903. The next prime is 9181909091923. The reversal of 9181909091909 is 9091909091819.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8903193727684 + 278715364225 = 2983822^2 + 527935^2 .

It is a cyclic number.

It is not a de Polignac number, because 9181909091909 - 2⁴ = 9181909091893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9181909091903) 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 in 3 ways as a sum of consecutive naturals, for example, 45454995404 + ... + 45454995605.

It is an arithmetic number, because the mean of its divisors is an integer number (2318204770755).

Almost surely, 2^{9181909091909} is an apocalyptic number.

It is an amenable number.

9181909091909 is a deficient number, since it is larger than the sum of its proper divisors (90909991111).

9181909091909 is a wasteful number, since it uses less digits than its factorization.

9181909091909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90909991110.

The product of its (nonzero) digits is 4251528, while the sum is 65.

The spelling of 9181909091909 in words is "nine trillion, one hundred eighty-one billion, nine hundred nine million, ninety-one thousand, nine hundred nine".