671995520 has 128 divisors (see below), whose sum is σ = 1866844800. Its totient is φ = 226529280.

The previous prime is 671995507. The next prime is 671995537. The reversal of 671995520 is 25599176.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

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 15 ways as a sum of consecutive naturals, for example, 272051 + ... + 274509.

It is an arithmetic number, because the mean of its divisors is an integer number (14584725).

Almost surely, 2^671995520 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 671995520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (933422400).

671995520 is an abundant number, since it is smaller than the sum of its proper divisors (1194849280).

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

671995520 is a wasteful number, since it uses less digits than its factorization.

671995520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2546 (or 2534 counting only the distinct ones).

The product of its (nonzero) digits is 170100, while the sum is 44.

The square root of 671995520 is about 25922.8763836114. The cubic root of 671995520 is about 875.9018815203.

The spelling of 671995520 in words is "six hundred seventy-one million, nine hundred ninety-five thousand, five hundred twenty".