81344672 has 12 divisors (see below), whose sum is σ = 160147386. Its totient is φ = 40672320.

The previous prime is 81344621. The next prime is 81344689. The reversal of 81344672 is 27644318.

It can be written as a sum of positive squares in only one way, i.e., 67831696 + 13512976 = 8236^2 + 3676^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1270979 + ... + 1271042.

Almost surely, 2^81344672 is an apocalyptic number.

It is an amenable number.

81344672 is a deficient number, since it is larger than the sum of its proper divisors (78802714).

81344672 is a wasteful number, since it uses less digits than its factorization.

81344672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2542031 (or 2542023 counting only the distinct ones).

The product of its digits is 32256, while the sum is 35.

The square root of 81344672 is about 9019.1281175067. The cubic root of 81344672 is about 433.2877101212.

The spelling of 81344672 in words is "eighty-one million, three hundred forty-four thousand, six hundred seventy-two".