671565540 has 48 divisors (see below), whose sum is σ = 1931211072. Its totient is φ = 174243456.

The previous prime is 671565473. The next prime is 671565541. The reversal of 671565540 is 45565176.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (671565541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 149034 + ... + 153473.

It is an arithmetic number, because the mean of its divisors is an integer number (40233564).

Almost surely, 2^671565540 is an apocalyptic number.

671565540 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

671565540 is an abundant number, since it is smaller than the sum of its proper divisors (1259645532).

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

671565540 is a wasteful number, since it uses less digits than its factorization.

671565540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 302556 (or 302554 counting only the distinct ones).

The product of its (nonzero) digits is 126000, while the sum is 39.

The square root of 671565540 is about 25914.5816095881. The cubic root of 671565540 is about 875.7150247949.

The spelling of 671565540 in words is "six hundred seventy-one million, five hundred sixty-five thousand, five hundred forty".