9181919090 has 16 divisors (see below), whose sum is σ = 16691094360. Its totient is φ = 3636403200.

The previous prime is 9181919041. The next prime is 9181919093. The reversal of 9181919090 is 909191819.

It is a happy number.

9181919090 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 8772382921 + 409536169 = 93661^2 + 20237^2 .

It is not an unprimeable number, because it can be changed into a prime (9181919093) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4544495 + ... + 4546514.

Almost surely, 2^9181919090 is an apocalyptic number.

9181919090 is a deficient number, since it is larger than the sum of its proper divisors (7509175270).

9181919090 is a wasteful number, since it uses less digits than its factorization.

9181919090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9091117.

The product of its (nonzero) digits is 52488, while the sum is 47.

The square root of 9181919090 is about 95822.3308524688. The cubic root of 9181919090 is about 2094.0055118602.

The spelling of 9181919090 in words is "nine billion, one hundred eighty-one million, nine hundred nineteen thousand, ninety".