671809680 has 320 divisors, whose sum is σ = 2437939200. Its totient is φ = 169827840.

The previous prime is 671809667. The next prime is 671809727. The reversal of 671809680 is 86908176.

It is a happy number.

It is a super-2 number, since 2×671809680² = 902656492283404800, which contains 22 as substring.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5289777 + ... + 5289903.

It is an arithmetic number, because the mean of its divisors is an integer number (7618560).

Almost surely, 2^671809680 is an apocalyptic number.

671809680 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 671809680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1218969600).

671809680 is an abundant number, since it is smaller than the sum of its proper divisors (1766129520).

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

671809680 is a wasteful number, since it uses less digits than its factorization.

671809680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259 (or 247 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 671809680 is about 25919.2916569879. The cubic root of 671809680 is about 875.8211306777.

It can be divided in two parts, 6718096 and 80, that added together give a palindrome (6718176).

The spelling of 671809680 in words is "six hundred seventy-one million, eight hundred nine thousand, six hundred eighty".