47391983809 has 3 divisors (see below), whose sum is σ = 47392201507. Its totient is φ = 47391766112.

The previous prime is 47391983783. The next prime is 47391983813. The reversal of 47391983809 is 90838919374.

The square root of 47391983809 is 217697.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 45324281025 + 2067702784 = 212895^2 + 45472^2 .

It is not a de Polignac number, because 47391983809 - 2⁵ = 47391983777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (47391983609) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 108849 + ... + 326545.

Almost surely, 2^47391983809 is an apocalyptic number.

47391983809 is the 217697-th square number.

47391983809 is the 108849-th centered octagonal number.

It is an amenable number.

47391983809 is a deficient number, since it is larger than the sum of its proper divisors (217698).

47391983809 is an frugal number, since it uses more digits than its factorization.

47391983809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 435394 (or 217697 counting only the distinct ones).

The product of its (nonzero) digits is 11757312, while the sum is 61.

The spelling of 47391983809 in words is "forty-seven billion, three hundred ninety-one million, nine hundred eighty-three thousand, eight hundred nine".