81442684 has 12 divisors (see below), whose sum is σ = 143068464. Its totient is φ = 40565984.

The previous prime is 81442679. The next prime is 81442703. The reversal of 81442684 is 48624418.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37657 + ... + 39760.

It is an arithmetic number, because the mean of its divisors is an integer number (11922372).

Almost surely, 2^81442684 is an apocalyptic number.

It is an amenable number.

81442684 is a deficient number, since it is larger than the sum of its proper divisors (61625780).

81442684 is a wasteful number, since it uses less digits than its factorization.

81442684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77684 (or 77682 counting only the distinct ones).

The product of its digits is 49152, while the sum is 37.

The square root of 81442684 is about 9024.5600446781. The cubic root of 81442684 is about 433.4616627154.

The spelling of 81442684 in words is "eighty-one million, four hundred forty-two thousand, six hundred eighty-four".