81884471 has 4 divisors (see below), whose sum is σ = 86194200. Its totient is φ = 77574744.

The previous prime is 81884443. The next prime is 81884497. The reversal of 81884471 is 17448818.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81884471 is a prime.

It is a super-3 number, since 3×81884471³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81884171) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2154836 + ... + 2154873.

It is an arithmetic number, because the mean of its divisors is an integer number (21548550).

Almost surely, 2^81884471 is an apocalyptic number.

81884471 is a deficient number, since it is larger than the sum of its proper divisors (4309729).

81884471 is a wasteful number, since it uses less digits than its factorization.

81884471 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4309728.

The product of its digits is 57344, while the sum is 41.

The square root of 81884471 is about 9049.0038678299. The cubic root of 81884471 is about 434.2440227639.

The spelling of 81884471 in words is "eighty-one million, eight hundred eighty-four thousand, four hundred seventy-one".