81647058 has 16 divisors (see below), whose sum is σ = 163663200. Its totient is φ = 27154176.

The previous prime is 81647051. The next prime is 81647063. The reversal of 81647058 is 85074618.

It is not an unprimeable number, because it can be changed into a prime (81647051) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12460 + ... + 17847.

It is an arithmetic number, because the mean of its divisors is an integer number (10228950).

Almost surely, 2^81647058 is an apocalyptic number.

81647058 is an abundant number, since it is smaller than the sum of its proper divisors (82016142).

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

81647058 is a wasteful number, since it uses less digits than its factorization.

81647058 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30761.

The product of its (nonzero) digits is 53760, while the sum is 39.

The square root of 81647058 is about 9035.8761611700. The cubic root of 81647058 is about 433.8239391486.

It can be divided in two parts, 816 and 47058, that added together give a palindrome (47874).

The spelling of 81647058 in words is "eighty-one million, six hundred forty-seven thousand, fifty-eight".