8161697778560 has 64 divisors (see below), whose sum is σ = 19531249027200. Its totient is φ = 3261384529920.

The previous prime is 8161697778541. The next prime is 8161697778629. The reversal of 8161697778560 is 658777961618.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×8161697778560² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5799995 + ... + 7068474.

It is an arithmetic number, because the mean of its divisors is an integer number (305175766050).

Almost surely, 2^{8161697778560} is an apocalyptic number.

8161697778560 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

8161697778560 is an abundant number, since it is smaller than the sum of its proper divisors (11369551248640).

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

8161697778560 is a wasteful number, since it uses less digits than its factorization.

8161697778560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12869479 (or 12869467 counting only the distinct ones).

The product of its (nonzero) digits is 213373440, while the sum is 71.

The spelling of 8161697778560 in words is "eight trillion, one hundred sixty-one billion, six hundred ninety-seven million, seven hundred seventy-eight thousand, five hundred sixty".