991043841 has 8 divisors (see below), whose sum is σ = 1353621024. Its totient is φ = 644581280.

The previous prime is 991043789. The next prime is 991043891. The reversal of 991043841 is 148340199.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 991043841 - 2⁶ = 991043777 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 991043841.

It is not an unprimeable number, because it can be changed into a prime (991043891) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4028511 + ... + 4028756.

It is an arithmetic number, because the mean of its divisors is an integer number (169202628).

Almost surely, 2^991043841 is an apocalyptic number.

It is an amenable number.

991043841 is a deficient number, since it is larger than the sum of its proper divisors (362577183).

991043841 is a wasteful number, since it uses less digits than its factorization.

991043841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8057311.

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 991043841 is about 31480.8487973244. The cubic root of 991043841 is about 997.0056565230.

The spelling of 991043841 in words is "nine hundred ninety-one million, forty-three thousand, eight hundred forty-one".