81363717 has 32 divisors (see below), whose sum is σ = 128943360. Its totient is φ = 50526720.

The previous prime is 81363713. The next prime is 81363727. The reversal of 81363717 is 71736318.

81363717 is a `hidden beast` number, since 8 + 1 + 3 + 637 + 17 = 666.

It is not a de Polignac number, because 81363717 - 2² = 81363713 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81363713) 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 31 ways as a sum of consecutive naturals, for example, 46417 + ... + 48137.

It is an arithmetic number, because the mean of its divisors is an integer number (4029480).

Almost surely, 2^81363717 is an apocalyptic number.

It is an amenable number.

81363717 is a deficient number, since it is larger than the sum of its proper divisors (47579643).

81363717 is a wasteful number, since it uses less digits than its factorization.

81363717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1850 (or 1844 counting only the distinct ones).

The product of its digits is 21168, while the sum is 36.

The square root of 81363717 is about 9020.1838673056. The cubic root of 81363717 is about 433.3215222948.

The spelling of 81363717 in words is "eighty-one million, three hundred sixty-three thousand, seven hundred seventeen".