81317716 has 12 divisors (see below), whose sum is σ = 142369920. Its totient is φ = 40640600.

The previous prime is 81317707. The next prime is 81317723. The reversal of 81317716 is 61771318.

It is a super-2 number, since 2×81317716² = 13225141870913312, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12765 + ... + 18043.

It is an arithmetic number, because the mean of its divisors is an integer number (11864160).

Almost surely, 2^81317716 is an apocalyptic number.

It is an amenable number.

81317716 is a deficient number, since it is larger than the sum of its proper divisors (61052204).

81317716 is a wasteful number, since it uses less digits than its factorization.

81317716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9134 (or 9132 counting only the distinct ones).

The product of its digits is 7056, while the sum is 34.

The square root of 81317716 is about 9017.6336142028. The cubic root of 81317716 is about 433.2398438684.

The spelling of 81317716 in words is "eighty-one million, three hundred seventeen thousand, seven hundred sixteen".