9491418991 has 4 divisors (see below), whose sum is σ = 9533981632. Its totient is φ = 9448856352.

The previous prime is 9491418977. The next prime is 9491419001. The reversal of 9491418991 is 1998141949.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1998141949 = 8719 ⋅229171.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9491418991 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 (9491418931) 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, 21280986 + ... + 21281431.

It is an arithmetic number, because the mean of its divisors is an integer number (2383495408).

Almost surely, 2^9491418991 is an apocalyptic number.

9491418991 is a deficient number, since it is larger than the sum of its proper divisors (42562641).

9491418991 is a wasteful number, since it uses less digits than its factorization.

9491418991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42562640.

The product of its digits is 839808, while the sum is 55.

The square root of 9491418991 is about 97423.9138558906. The cubic root of 9491418991 is about 2117.2739221339.

The spelling of 9491418991 in words is "nine billion, four hundred ninety-one million, four hundred eighteen thousand, nine hundred ninety-one".