81676871 has 4 divisors (see below), whose sum is σ = 83884392. Its totient is φ = 79469352.

The previous prime is 81676867. The next prime is 81676901. The reversal of 81676871 is 17867618.

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 81676871 - 2² = 81676867 is a prime.

It is a super-2 number, since 2×81676871² = 13342222512701282, which contains 22 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 (81676811) 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, 1103705 + ... + 1103778.

It is an arithmetic number, because the mean of its divisors is an integer number (20971098).

Almost surely, 2^81676871 is an apocalyptic number.

81676871 is a deficient number, since it is larger than the sum of its proper divisors (2207521).

81676871 is a wasteful number, since it uses less digits than its factorization.

81676871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2207520.

The product of its digits is 112896, while the sum is 44.

The square root of 81676871 is about 9037.5257122732. The cubic root of 81676871 is about 433.8767355772.

The spelling of 81676871 in words is "eighty-one million, six hundred seventy-six thousand, eight hundred seventy-one".