81078851 has 4 divisors (see below), whose sum is σ = 92661552. Its totient is φ = 69496152.

The previous prime is 81078847. The next prime is 81078859. The reversal of 81078851 is 15887018.

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 81078851 - 2² = 81078847 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81078859) 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, 5791340 + ... + 5791353.

It is an arithmetic number, because the mean of its divisors is an integer number (23165388).

Almost surely, 2^81078851 is an apocalyptic number.

81078851 is a deficient number, since it is larger than the sum of its proper divisors (11582701).

81078851 is a wasteful number, since it uses less digits than its factorization.

81078851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11582700.

The product of its (nonzero) digits is 17920, while the sum is 38.

The square root of 81078851 is about 9004.3795455323. The cubic root of 81078851 is about 432.8152241032.

The spelling of 81078851 in words is "eighty-one million, seventy-eight thousand, eight hundred fifty-one".