81439284 has 24 divisors (see below), whose sum is σ = 194660928. Its totient is φ = 26484160.

The previous prime is 81439277. The next prime is 81439289. The reversal of 81439284 is 48293418.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81439289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 82272 + ... + 83255.

It is an arithmetic number, because the mean of its divisors is an integer number (8110872).

Almost surely, 2^81439284 is an apocalyptic number.

It is an amenable number.

81439284 is an abundant number, since it is smaller than the sum of its proper divisors (113221644).

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

81439284 is a wasteful number, since it uses less digits than its factorization.

81439284 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165575 (or 165573 counting only the distinct ones).

The product of its digits is 55296, while the sum is 39.

The square root of 81439284 is about 9024.3716678780. The cubic root of 81439284 is about 433.4556307017.

The spelling of 81439284 in words is "eighty-one million, four hundred thirty-nine thousand, two hundred eighty-four".