81578795 has 4 divisors (see below), whose sum is σ = 97894560. Its totient is φ = 65263032.

The previous prime is 81578789. The next prime is 81578813. The reversal of 81578795 is 59787518.

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 81578795 - 2⁴ = 81578779 is a prime.

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, 8157875 + ... + 8157884.

It is an arithmetic number, because the mean of its divisors is an integer number (24473640).

Almost surely, 2^81578795 is an apocalyptic number.

81578795 is a deficient number, since it is larger than the sum of its proper divisors (16315765).

81578795 is a wasteful number, since it uses less digits than its factorization.

81578795 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16315764.

The product of its digits is 705600, while the sum is 50.

The square root of 81578795 is about 9032.0980397691. The cubic root of 81578795 is about 433.7030024350.

The spelling of 81578795 in words is "eighty-one million, five hundred seventy-eight thousand, seven hundred ninety-five".