81447412 has 12 divisors (see below), whose sum is σ = 143089380. Its totient is φ = 40564736.

The previous prime is 81447389. The next prime is 81447419. The reversal of 81447412 is 21474418.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 76807696 + 4639716 = 8764^2 + 2154^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81447419) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38587 + ... + 40642.

It is an arithmetic number, because the mean of its divisors is an integer number (11924115).

Almost surely, 2^81447412 is an apocalyptic number.

It is an amenable number.

81447412 is a deficient number, since it is larger than the sum of its proper divisors (61641968).

81447412 is a wasteful number, since it uses less digits than its factorization.

81447412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79490 (or 79488 counting only the distinct ones).

The product of its digits is 7168, while the sum is 31.

The square root of 81447412 is about 9024.8219927043. The cubic root of 81447412 is about 433.4700504837.

The spelling of 81447412 in words is "eighty-one million, four hundred forty-seven thousand, four hundred twelve".