81758299685 has 16 divisors (see below), whose sum is σ = 98264399232. Its totient is φ = 65303755200.

The previous prime is 81758299661. The next prime is 81758299697. The reversal of 81758299685 is 58699285718.

It is not a de Polignac number, because 81758299685 - 2¹⁴ = 81758283301 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19185455 + ... + 19189715.

It is an arithmetic number, because the mean of its divisors is an integer number (6141524952).

Almost surely, 2^81758299685 is an apocalyptic number.

It is an amenable number.

81758299685 is a deficient number, since it is larger than the sum of its proper divisors (16506099547).

81758299685 is a wasteful number, since it uses less digits than its factorization.

81758299685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9404.

The product of its digits is 87091200, while the sum is 68.

The spelling of 81758299685 in words is "eighty-one billion, seven hundred fifty-eight million, two hundred ninety-nine thousand, six hundred eighty-five".