81338785 has 8 divisors (see below), whose sum is σ = 106479936. Its totient is φ = 59155440.

The previous prime is 81338783. The next prime is 81338797. The reversal of 81338785 is 58783318.

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

It is not a de Polignac number, because 81338785 - 2¹ = 81338783 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81338783) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 739389 + ... + 739498.

It is an arithmetic number, because the mean of its divisors is an integer number (13309992).

Almost surely, 2^81338785 is an apocalyptic number.

It is an amenable number.

81338785 is a deficient number, since it is larger than the sum of its proper divisors (25141151).

81338785 is a wasteful number, since it uses less digits than its factorization.

81338785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1478903.

The product of its digits is 161280, while the sum is 43.

The square root of 81338785 is about 9018.8017496783. The cubic root of 81338785 is about 433.2772573723.

The spelling of 81338785 in words is "eighty-one million, three hundred thirty-eight thousand, seven hundred eighty-five".