81680400717168 has 40 divisors (see below), whose sum is σ = 230190220204416. Its totient is φ = 24751636580800.

The previous prime is 81680400717131. The next prime is 81680400717173. The reversal of 81680400717168 is 86171700408618.

It is a super-2 number, since 2×81680400717168² (a number of 29 digits) 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 7 ways as a sum of consecutive naturals, for example, 77348863788 + ... + 77348864843.

Almost surely, 2^{81680400717168} is an apocalyptic number.

81680400717168 is a gapful number since it is divisible by the number (88) formed by its first and last digit.

It is an amenable number.

81680400717168 is an abundant number, since it is smaller than the sum of its proper divisors (148509819487248).

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

81680400717168 is a wasteful number, since it uses less digits than its factorization.

81680400717168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154697728653 (or 154697728647 counting only the distinct ones).

The product of its (nonzero) digits is 3612672, while the sum is 57.

The spelling of 81680400717168 in words is "eighty-one trillion, six hundred eighty billion, four hundred million, seven hundred seventeen thousand, one hundred sixty-eight".