81672395489280 has 1904 divisors, whose sum is σ = 311918445699840. Its totient is φ = 20486239027200.

The previous prime is 81672395489227. The next prime is 81672395489339. The reversal of 81672395489280 is 8298459327618.

81672395489280 is a `hidden beast` number, since 8 + 1 + 6 + 72 + 3 + 9 + 548 + 9 + 2 + 8 + 0 = 666.

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 = 81672395489199 and 81672395489208.

It is a congruent number.

It is an unprimeable number.

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 111 ways as a sum of consecutive naturals, for example, 303614852986 + ... + 303614853254.

It is a 1-persistent number, because it is pandigital, but 2⋅81672395489280 = 163344790978560 is not.

Almost surely, 2^{81672395489280} is an apocalyptic number.

81672395489280 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 81672395489280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (155959222849920).

81672395489280 is an abundant number, since it is smaller than the sum of its proper divisors (230246050210560).

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

81672395489280 is an frugal number, since it uses more digits than its factorization.

81672395489280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396 (or 351 counting only the distinct ones).

The product of its (nonzero) digits is 418037760, while the sum is 72.

The spelling of 81672395489280 in words is "eighty-one trillion, six hundred seventy-two billion, three hundred ninety-five million, four hundred eighty-nine thousand, two hundred eighty".