81842586 has 32 divisors (see below), whose sum is σ = 189006720. Its totient is φ = 23141376.

The previous prime is 81842569. The next prime is 81842587. The reversal of 81842586 is 68524818.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (81842587) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5971 + ... + 14118.

It is an arithmetic number, because the mean of its divisors is an integer number (5906460).

Almost surely, 2^81842586 is an apocalyptic number.

81842586 is an abundant number, since it is smaller than the sum of its proper divisors (107164134).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81842586 is a wasteful number, since it uses less digits than its factorization.

81842586 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20198.

The product of its digits is 122880, while the sum is 42.

The square root of 81842586 is about 9046.6892286626. The cubic root of 81842586 is about 434.1699695979.

It can be divided in two parts, 81842 and 586, that added together give a palindrome (82428).

The spelling of 81842586 in words is "eighty-one million, eight hundred forty-two thousand, five hundred eighty-six".