9447991 has 4 divisors (see below), whose sum is σ = 10797712. Its totient is φ = 8098272.

The previous prime is 9447983. The next prime is 9448001. The reversal of 9447991 is 1997449.

9447991 is digitally balanced in base 3, 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 an emirpimes, since its reverse is a distinct semiprime: 1997449 = 17 ⋅117497.

It is not a de Polignac number, because 9447991 - 2³ = 9447983 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9447391) 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, 674850 + ... + 674863.

It is an arithmetic number, because the mean of its divisors is an integer number (2699428).

Almost surely, 2^9447991 is an apocalyptic number.

9447991 is a deficient number, since it is larger than the sum of its proper divisors (1349721).

9447991 is a wasteful number, since it uses less digits than its factorization.

9447991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1349720.

The product of its digits is 81648, while the sum is 43.

The square root of 9447991 is about 3073.7584485447. The cubic root of 9447991 is about 211.4039788650.

It can be divided in two parts, 94 and 47991, that multiplied together give a palindrome (4511154).

The spelling of 9447991 in words is "nine million, four hundred forty-seven thousand, nine hundred ninety-one".