9181663985 has 16 divisors (see below), whose sum is σ = 11925177600. Its totient is φ = 6746224320.

The previous prime is 9181663961. The next prime is 9181663999. The reversal of 9181663985 is 5893661819.

It is not a de Polignac number, because 9181663985 - 2⁶ = 9181663921 is a prime.

It is a Smith number, since the sum of its digits (56) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 9181663985.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 341981 + ... + 367850.

It is an arithmetic number, because the mean of its divisors is an integer number (745323600).

Almost surely, 2^9181663985 is an apocalyptic number.

It is an amenable number.

9181663985 is a deficient number, since it is larger than the sum of its proper divisors (2743513615).

9181663985 is a wasteful number, since it uses less digits than its factorization.

9181663985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 710048.

The product of its digits is 2799360, while the sum is 56.

The square root of 9181663985 is about 95820.9997077885. Note that the first 3 decimals coincide. The cubic root of 9181663985 is about 2093.9861188111.

Adding to 9181663985 its sum of digits (56), we get a square (9181664041 = 95821²).

The spelling of 9181663985 in words is "nine billion, one hundred eighty-one million, six hundred sixty-three thousand, nine hundred eighty-five".