991398041 has 4 divisors (see below), whose sum is σ = 991463952. Its totient is φ = 991332132.

The previous prime is 991398007. The next prime is 991398101. The reversal of 991398041 is 140893199.

991398041 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 140893199 = 4591 ⋅30689.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-991398041 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 991397983 and 991398001.

It is not an unprimeable number, because it can be changed into a prime (991398241) 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, 1886 + ... + 44568.

It is an arithmetic number, because the mean of its divisors is an integer number (247865988).

Almost surely, 2^991398041 is an apocalyptic number.

It is an amenable number.

991398041 is a deficient number, since it is larger than the sum of its proper divisors (65911).

991398041 is a wasteful number, since it uses less digits than its factorization.

991398041 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65910.

The product of its (nonzero) digits is 69984, while the sum is 44.

The square root of 991398041 is about 31486.4739372322. The cubic root of 991398041 is about 997.1244192950.

The spelling of 991398041 in words is "nine hundred ninety-one million, three hundred ninety-eight thousand, forty-one".