47128809 has 16 divisors (see below), whose sum is σ = 77340032. Its totient is φ = 24859008.

The previous prime is 47128801. The next prime is 47128831. The reversal of 47128809 is 90882174.

47128809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 47128809 - 2³ = 47128801 is a prime.

It is a super-2 number, since 2×47128809² = 4442249275516962, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (47128801) 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 15 ways as a sum of consecutive naturals, for example, 86044 + ... + 86589.

It is an arithmetic number, because the mean of its divisors is an integer number (4833752).

Almost surely, 2^47128809 is an apocalyptic number.

It is an amenable number.

47128809 is a deficient number, since it is larger than the sum of its proper divisors (30211223).

47128809 is a wasteful number, since it uses less digits than its factorization.

47128809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172656.

The product of its (nonzero) digits is 32256, while the sum is 39.

The square root of 47128809 is about 6865.0425344640. The cubic root of 47128809 is about 361.2119876351.

The spelling of 47128809 in words is "forty-seven million, one hundred twenty-eight thousand, eight hundred nine".