9891813841 has 64 divisors (see below), whose sum is σ = 12933043200. Its totient is φ = 7355851776.

The previous prime is 9891813809. The next prime is 9891813859. The reversal of 9891813841 is 1483181989.

It is not a de Polignac number, because 9891813841 - 2⁵ = 9891813809 is a prime.

It is not an unprimeable number, because it can be changed into a prime (9891813541) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 27553620 + ... + 27553978.

It is an arithmetic number, because the mean of its divisors is an integer number (202078800).

Almost surely, 2^9891813841 is an apocalyptic number.

9891813841 is a gapful number since it is divisible by the number (91) formed by its first and last digit.

It is an amenable number.

9891813841 is a deficient number, since it is larger than the sum of its proper divisors (3041229359).

9891813841 is a wasteful number, since it uses less digits than its factorization.

9891813841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 658.

The product of its digits is 497664, while the sum is 52.

The square root of 9891813841 is about 99457.5982064719. The cubic root of 9891813841 is about 2146.6371688006.

The spelling of 9891813841 in words is "nine billion, eight hundred ninety-one million, eight hundred thirteen thousand, eight hundred forty-one".