9991047 has 8 divisors (see below), whose sum is σ = 14532480. Its totient is φ = 6055160.

The previous prime is 9991027. The next prime is 9991057. The reversal of 9991047 is 7401999.

9991047 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

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 9991047 - 2⁷ = 9990919 is a prime.

9991047 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 9990996 and 9991014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9991027) 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, 151347 + ... + 151412.

It is an arithmetic number, because the mean of its divisors is an integer number (1816560).

Almost surely, 2^9991047 is an apocalyptic number.

9991047 is a deficient number, since it is larger than the sum of its proper divisors (4541433).

9991047 is a wasteful number, since it uses less digits than its factorization.

9991047 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 302773.

The product of its (nonzero) digits is 20412, while the sum is 39.

The square root of 9991047 is about 3160.8617495867. The cubic root of 9991047 is about 215.3791542931.

The spelling of 9991047 in words is "nine million, nine hundred ninety-one thousand, forty-seven".