47991117 has 4 divisors (see below), whose sum is σ = 63988160. Its totient is φ = 31994076.

The previous prime is 47991107. The next prime is 47991121. The reversal of 47991117 is 71119974.

47991117 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.

It is not a de Polignac number, because 47991117 - 2⁸ = 47990861 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (47991107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7998517 + ... + 7998522.

It is an arithmetic number, because the mean of its divisors is an integer number (15997040).

Almost surely, 2^47991117 is an apocalyptic number.

It is an amenable number.

47991117 is a deficient number, since it is larger than the sum of its proper divisors (15997043).

47991117 is a wasteful number, since it uses less digits than its factorization.

47991117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15997042.

The product of its digits is 15876, while the sum is 39.

The square root of 47991117 is about 6927.5621253079. The cubic root of 47991117 is about 363.4016984580.

The spelling of 47991117 in words is "forty-seven million, nine hundred ninety-one thousand, one hundred seventeen".