81368645 has 8 divisors (see below), whose sum is σ = 100792320. Its totient is φ = 62994960.

The previous prime is 81368593. The next prime is 81368653. The reversal of 81368645 is 54686318.

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

It is not a de Polignac number, because 81368645 - 2⁸ = 81368389 is a prime.

It is a congruent 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 7 ways as a sum of consecutive naturals, for example, 262325 + ... + 262634.

It is an arithmetic number, because the mean of its divisors is an integer number (12599040).

Almost surely, 2^81368645 is an apocalyptic number.

It is an amenable number.

81368645 is a deficient number, since it is larger than the sum of its proper divisors (19423675).

81368645 is a wasteful number, since it uses less digits than its factorization.

81368645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 524995.

The product of its digits is 138240, while the sum is 41.

The square root of 81368645 is about 9020.4570283329. The cubic root of 81368645 is about 433.3302705240.

The spelling of 81368645 in words is "eighty-one million, three hundred sixty-eight thousand, six hundred forty-five".