81671471 has 4 divisors (see below), whose sum is σ = 93338832. Its totient is φ = 70004112.

The previous prime is 81671461. The next prime is 81671489. The reversal of 81671471 is 17417618.

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

It is a cyclic number.

It is not a de Polignac number, because 81671471 - 2¹⁴ = 81655087 is a prime.

It is a super-3 number, since 3×81671471³ (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 (81671441) 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, 5833670 + ... + 5833683.

It is an arithmetic number, because the mean of its divisors is an integer number (23334708).

Almost surely, 2^81671471 is an apocalyptic number.

81671471 is a deficient number, since it is larger than the sum of its proper divisors (11667361).

81671471 is a wasteful number, since it uses less digits than its factorization.

81671471 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11667360.

The product of its digits is 9408, while the sum is 35.

The square root of 81671471 is about 9037.2269529984. The cubic root of 81671471 is about 433.8671735638.

The spelling of 81671471 in words is "eighty-one million, six hundred seventy-one thousand, four hundred seventy-one".