671543840 has 48 divisors (see below), whose sum is σ = 1730756160. Its totient is φ = 244197120.

The previous prime is 671543837. The next prime is 671543897. The reversal of 671543840 is 48345176.

It is a super-2 number, since 2×671543840² = 901942258083891200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 671543794 and 671543803.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 189020 + ... + 192539.

It is an arithmetic number, because the mean of its divisors is an integer number (36057420).

Almost surely, 2^671543840 is an apocalyptic number.

It is an amenable number.

671543840 is an abundant number, since it is smaller than the sum of its proper divisors (1059212320).

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

671543840 is a wasteful number, since it uses less digits than its factorization.

671543840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 381585 (or 381577 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 38.

The square root of 671543840 is about 25914.1629230041. The cubic root of 671543840 is about 875.7055924960.

The spelling of 671543840 in words is "six hundred seventy-one million, five hundred forty-three thousand, eight hundred forty".