81676671 has 4 divisors (see below), whose sum is σ = 108902232. Its totient is φ = 54451112.

The previous prime is 81676669. The next prime is 81676681. The reversal of 81676671 is 17667618.

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 81676671 - 2¹ = 81676669 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81676681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13612776 + ... + 13612781.

It is an arithmetic number, because the mean of its divisors is an integer number (27225558).

Almost surely, 2^81676671 is an apocalyptic number.

81676671 is a deficient number, since it is larger than the sum of its proper divisors (27225561).

81676671 is a wasteful number, since it uses less digits than its factorization.

81676671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27225560.

The product of its digits is 84672, while the sum is 42.

The square root of 81676671 is about 9037.5146472910. The cubic root of 81676671 is about 433.8763814361.

The spelling of 81676671 in words is "eighty-one million, six hundred seventy-six thousand, six hundred seventy-one".