9181819091909 has 4 divisors (see below), whose sum is σ = 9184052571840. Its totient is φ = 9179585611980.

The previous prime is 9181819091899. The next prime is 9181819091917. The reversal of 9181819091909 is 9091909181819.

9181819091909 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9181819091909 is a prime.

It is a super-2 number, since 2×9181819091909² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9181819091009) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1116733799 + ... + 1116742020.

It is an arithmetic number, because the mean of its divisors is an integer number (2296013142960).

Almost surely, 2^{9181819091909} is an apocalyptic number.

It is an amenable number.

9181819091909 is a deficient number, since it is larger than the sum of its proper divisors (2233479931).

9181819091909 is a wasteful number, since it uses less digits than its factorization.

9181819091909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2233479930.

The product of its (nonzero) digits is 3779136, while the sum is 65.

The spelling of 9181819091909 in words is "nine trillion, one hundred eighty-one billion, eight hundred nineteen million, ninety-one thousand, nine hundred nine".