47091809 has 2 divisors, whose sum is σ = 47091810. Its totient is φ = 47091808.

The previous prime is 47091799. The next prime is 47091827. The reversal of 47091809 is 90819074.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 43191184 + 3900625 = 6572^2 + 1975^2 .

It is a cyclic number.

It is not a de Polignac number, because 47091809 - 2²⁴ = 30314593 is a prime.

It is not a weakly prime, because it can be changed into another prime (47091859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 23545904 + 23545905.

It is an arithmetic number, because the mean of its divisors is an integer number (23545905).

Almost surely, 2^47091809 is an apocalyptic number.

It is an amenable number.

47091809 is a deficient number, since it is larger than the sum of its proper divisors (1).

47091809 is an equidigital number, since it uses as much as digits as its factorization.

47091809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 47091809 is about 6862.3471931985. The cubic root of 47091809 is about 361.1174358252.

The spelling of 47091809 in words is "forty-seven million, ninety-one thousand, eight hundred nine".