81100678 has 4 divisors (see below), whose sum is σ = 121651020. Its totient is φ = 40550338.

The previous prime is 81100667. The next prime is 81100697. The reversal of 81100678 is 87600118.

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

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20275168 + ... + 20275171.

It is an arithmetic number, because the mean of its divisors is an integer number (30412755).

Almost surely, 2^81100678 is an apocalyptic number.

81100678 is a deficient number, since it is larger than the sum of its proper divisors (40550342).

81100678 is a wasteful number, since it uses less digits than its factorization.

81100678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40550341.

The product of its (nonzero) digits is 2688, while the sum is 31.

The square root of 81100678 is about 9005.5914852940. The cubic root of 81100678 is about 432.8540595914.

The spelling of 81100678 in words is "eighty-one million, one hundred thousand, six hundred seventy-eight".