81079806487680 has 1920 divisors, whose sum is σ = 395711322874560. Its totient is φ = 15551701401600.

The previous prime is 81079806487661. The next prime is 81079806487711. The reversal of 81079806487680 is 8678460897018.

81079806487680 is a `hidden beast` number, since 8 + 1 + 0 + 7 + 9 + 80 + 6 + 487 + 68 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1920).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 81079806487599 and 81079806487608.

It is an unprimeable number.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 363131275 + ... + 363354485.

Almost surely, 2^{81079806487680} is an apocalyptic number.

81079806487680 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81079806487680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (197855661437280).

81079806487680 is an abundant number, since it is smaller than the sum of its proper divisors (314631516386880).

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

81079806487680 is a wasteful number, since it uses less digits than its factorization.

81079806487680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223280 (or 223252 counting only the distinct ones).

The product of its (nonzero) digits is 260112384, while the sum is 72.

The spelling of 81079806487680 in words is "eighty-one trillion, seventy-nine billion, eight hundred six million, four hundred eighty-seven thousand, six hundred eighty".