671863680 has 256 divisors, whose sum is σ = 2423520000. Its totient is φ = 175859712.

The previous prime is 671863657. The next prime is 671863697. The reversal of 671863680 is 86368176.

671863680 is a `hidden beast` number, since 6 + 7 + 1 + 8 + 636 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1019191 + ... + 1019849.

It is an arithmetic number, because the mean of its divisors is an integer number (9466875).

Almost surely, 2^671863680 is an apocalyptic number.

671863680 is a gapful number since it is divisible by the number (60) 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 671863680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1211760000).

671863680 is an abundant number, since it is smaller than the sum of its proper divisors (1751656320).

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

671863680 is a wasteful number, since it uses less digits than its factorization.

671863680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 746 (or 728 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The square root of 671863680 is about 25920.3333311900. Note that the first 5 decimals coincide. The cubic root of 671863680 is about 875.8445961895.

The spelling of 671863680 in words is "six hundred seventy-one million, eight hundred sixty-three thousand, six hundred eighty".