81578794 has 16 divisors (see below), whose sum is σ = 137799936. Its totient is φ = 35884800.

The previous prime is 81578789. The next prime is 81578813. The reversal of 81578794 is 49787518.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59127 + ... + 60490.

It is an arithmetic number, because the mean of its divisors is an integer number (8612496).

Almost surely, 2^81578794 is an apocalyptic number.

81578794 is a deficient number, since it is larger than the sum of its proper divisors (56221142).

81578794 is a wasteful number, since it uses less digits than its factorization.

81578794 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119661.

The product of its digits is 564480, while the sum is 49.

The square root of 81578794 is about 9032.0979844109. The cubic root of 81578794 is about 433.7030006629.

It can be divided in two parts, 81 and 578794, that added together give a palindrome (578875).

The spelling of 81578794 in words is "eighty-one million, five hundred seventy-eight thousand, seven hundred ninety-four".