47809891 has 4 divisors (see below), whose sum is σ = 48174984. Its totient is φ = 47444800.

The previous prime is 47809877. The next prime is 47809897. The reversal of 47809891 is 19890874.

It is a happy number.

47809891 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.

It is a cyclic number.

It is not a de Polignac number, because 47809891 - 2¹¹ = 47807843 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (47809897) 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, 182350 + ... + 182611.

It is an arithmetic number, because the mean of its divisors is an integer number (12043746).

Almost surely, 2^47809891 is an apocalyptic number.

47809891 is a deficient number, since it is larger than the sum of its proper divisors (365093).

47809891 is a wasteful number, since it uses less digits than its factorization.

47809891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 365092.

The product of its (nonzero) digits is 145152, while the sum is 46.

The square root of 47809891 is about 6914.4696832078. The cubic root of 47809891 is about 362.9436907195.

The spelling of 47809891 in words is "forty-seven million, eight hundred nine thousand, eight hundred ninety-one".