671872128 has 64 divisors (see below), whose sum is σ = 1788035520. Its totient is φ = 223534080.

The previous prime is 671872121. The next prime is 671872133. The reversal of 671872128 is 821278176.

It is a tau number, because it is divible by the number of its divisors (64).

It is a self number, because there is not a number n which added to its sum of digits gives 671872128.

It is not an unprimeable number, because it can be changed into a prime (671872121) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 252501 + ... + 255147.

It is an arithmetic number, because the mean of its divisors is an integer number (27938055).

Almost surely, 2^671872128 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 671872128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (894017760).

671872128 is an abundant number, since it is smaller than the sum of its proper divisors (1116163392).

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

671872128 is a wasteful number, since it uses less digits than its factorization.

671872128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3325 (or 3313 counting only the distinct ones).

The product of its digits is 75264, while the sum is 42.

The square root of 671872128 is about 25920.4962915450. The cubic root of 671872128 is about 875.8482671248.

The spelling of 671872128 in words is "six hundred seventy-one million, eight hundred seventy-two thousand, one hundred twenty-eight".