81717693 has 4 divisors (see below), whose sum is σ = 108956928. Its totient is φ = 54478460.

The previous prime is 81717677. The next prime is 81717703. The reversal of 81717693 is 39671718.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81717693 - 2⁴ = 81717677 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81717653) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13619613 + ... + 13619618.

It is an arithmetic number, because the mean of its divisors is an integer number (27239232).

Almost surely, 2^81717693 is an apocalyptic number.

It is an amenable number.

81717693 is a deficient number, since it is larger than the sum of its proper divisors (27239235).

81717693 is a wasteful number, since it uses less digits than its factorization.

81717693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27239234.

The product of its digits is 63504, while the sum is 42.

The square root of 81717693 is about 9039.7839022844. The cubic root of 81717693 is about 433.9490072250.

The spelling of 81717693 in words is "eighty-one million, seven hundred seventeen thousand, six hundred ninety-three".