81695868 has 24 divisors (see below), whose sum is σ = 191587200. Its totient is φ = 27094320.

The previous prime is 81695807. The next prime is 81695893. The reversal of 81695868 is 86859618.

It is a self number, because there is not a number n which added to its sum of digits gives 81695868.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14718 + ... + 19493.

It is an arithmetic number, because the mean of its divisors is an integer number (7982800).

Almost surely, 2^81695868 is an apocalyptic number.

It is an amenable number.

81695868 is an abundant number, since it is smaller than the sum of its proper divisors (109891332).

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

81695868 is a wasteful number, since it uses less digits than its factorization.

81695868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34417 (or 34415 counting only the distinct ones).

The product of its digits is 829440, while the sum is 51.

The square root of 81695868 is about 9038.5766578594. The cubic root of 81695868 is about 433.9103710373.

The spelling of 81695868 in words is "eighty-one million, six hundred ninety-five thousand, eight hundred sixty-eight".