81678535 has 4 divisors (see below), whose sum is σ = 98014248. Its totient is φ = 65342824.

The previous prime is 81678517. The next prime is 81678563. The reversal of 81678535 is 53587618.

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 81678535 - 2⁵ = 81678503 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81678491 and 81678500.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8167849 + ... + 8167858.

It is an arithmetic number, because the mean of its divisors is an integer number (24503562).

Almost surely, 2^81678535 is an apocalyptic number.

81678535 is a deficient number, since it is larger than the sum of its proper divisors (16335713).

81678535 is a wasteful number, since it uses less digits than its factorization.

81678535 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16335712.

The product of its digits is 201600, while the sum is 43.

The square root of 81678535 is about 9037.6177724000. The cubic root of 81678535 is about 433.8796820090.

The spelling of 81678535 in words is "eighty-one million, six hundred seventy-eight thousand, five hundred thirty-five".