81697597317 has 48 divisors (see below), whose sum is σ = 142082703360. Its totient is φ = 44190315936.

The previous prime is 81697597291. The next prime is 81697597367. The reversal of 81697597317 is 71379579618.

81697597317 is a `hidden beast` number, since 8 + 1 + 6 + 9 + 7 + 597 + 31 + 7 = 666.

It is not a de Polignac number, because 81697597317 - 2¹⁴ = 81697580933 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81697597367) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1436028 + ... + 1491834.

It is an arithmetic number, because the mean of its divisors is an integer number (2960056320).

Almost surely, 2^81697597317 is an apocalyptic number.

It is an amenable number.

81697597317 is a deficient number, since it is larger than the sum of its proper divisors (60385106043).

81697597317 is a wasteful number, since it uses less digits than its factorization.

81697597317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57062 (or 57059 counting only the distinct ones).

The product of its digits is 20003760, while the sum is 63.

The spelling of 81697597317 in words is "eighty-one billion, six hundred ninety-seven million, five hundred ninety-seven thousand, three hundred seventeen".