47991881 has 8 divisors (see below), whose sum is σ = 54893184. Its totient is φ = 41101920.

The previous prime is 47991851. The next prime is 47991883. The reversal of 47991881 is 18819974.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 47991881 - 2²² = 43797577 is a prime.

It is a super-2 number, since 2×47991881² = 4606441283836322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (47991883) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10316 + ... + 14226.

It is an arithmetic number, because the mean of its divisors is an integer number (6861648).

Almost surely, 2^47991881 is an apocalyptic number.

It is an amenable number.

47991881 is a deficient number, since it is larger than the sum of its proper divisors (6901303).

47991881 is a wasteful number, since it uses less digits than its factorization.

47991881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5671.

The product of its digits is 145152, while the sum is 47.

The square root of 47991881 is about 6927.6172671417. The cubic root of 47991881 is about 363.4036268526.

The spelling of 47991881 in words is "forty-seven million, nine hundred ninety-one thousand, eight hundred eighty-one".