81744906 has 8 divisors (see below), whose sum is σ = 163489824. Its totient is φ = 27248300.

The previous prime is 81744899. The next prime is 81744919. The reversal of 81744906 is 60944718.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

81744906 is an admirable number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 6812070 + ... + 6812081.

It is an arithmetic number, because the mean of its divisors is an integer number (20436228).

Almost surely, 2^81744906 is an apocalyptic number.

81744906 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

81744906 is a wasteful number, since it uses less digits than its factorization.

81744906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13624156.

The product of its (nonzero) digits is 48384, while the sum is 39.

The square root of 81744906 is about 9041.2889567804. The cubic root of 81744906 is about 433.9971720033.

The spelling of 81744906 in words is "eighty-one million, seven hundred forty-four thousand, nine hundred six".