9491388890 has 32 divisors (see below), whose sum is σ = 17681693904. Its totient is φ = 3665756160.

The previous prime is 9491388871. The next prime is 9491388911. The reversal of 9491388890 is 988831949.

It can be written as a sum of positive squares in 8 ways, for example, as 3041853409 + 6449535481 = 55153^2 + 80309^2 .

It is a super-2 number, since 2×9491388890² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (59) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 79559 + ... + 159098.

Almost surely, 2^9491388890 is an apocalyptic number.

9491388890 is a deficient number, since it is larger than the sum of its proper divisors (8190305014).

9491388890 is a wasteful number, since it uses less digits than its factorization.

9491388890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238802.

The product of its (nonzero) digits is 4478976, while the sum is 59.

The square root of 9491388890 is about 97423.7593711103. The cubic root of 9491388890 is about 2117.2716838971.

The spelling of 9491388890 in words is "nine billion, four hundred ninety-one million, three hundred eighty-eight thousand, eight hundred ninety".