820667671680 has 64 divisors (see below), whose sum is σ = 2615878209600. Its totient is φ = 218844711936.

The previous prime is 820667671679. The next prime is 820667671687. The reversal of 820667671680 is 86176766028.

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

It is a self number, because there is not a number n which added to its sum of digits gives 820667671680.

It is not an unprimeable number, because it can be changed into a prime (820667671687) by changing a digit.

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, 213713620 + ... + 213717459.

It is an arithmetic number, because the mean of its divisors is an integer number (40873097025).

Almost surely, 2^820667671680 is an apocalyptic number.

820667671680 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

820667671680 is an abundant number, since it is smaller than the sum of its proper divisors (1795210537920).

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

820667671680 is a wasteful number, since it uses less digits than its factorization.

820667671680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 427431101 (or 427431089 counting only the distinct ones).

The product of its (nonzero) digits is 8128512, while the sum is 57.

The spelling of 820667671680 in words is "eight hundred twenty billion, six hundred sixty-seven million, six hundred seventy-one thousand, six hundred eighty".