671963904 has 144 divisors (see below), whose sum is σ = 2018163840. Its totient is φ = 220492800.

The previous prime is 671963891. The next prime is 671963909. The reversal of 671963904 is 409369176.

671963904 is a `hidden beast` number, since 6 + 7 + 1 + 9 + 639 + 0 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a self number, because there is not a number n which added to its sum of digits gives 671963904.

It is not an unprimeable number, because it can be changed into a prime (671963909) 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, 462379 + ... + 463829.

Almost surely, 2^671963904 is an apocalyptic number.

671963904 is a gapful number since it is divisible by the number (64) 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 671963904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1009081920).

671963904 is an abundant number, since it is smaller than the sum of its proper divisors (1346199936).

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

671963904 is a wasteful number, since it uses less digits than its factorization.

671963904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1543 (or 1523 counting only the distinct ones).

The product of its (nonzero) digits is 244944, while the sum is 45.

The square root of 671963904 is about 25922.2665675670. The cubic root of 671963904 is about 875.8881448473. Note that the first 3 decimals are identical.

The spelling of 671963904 in words is "six hundred seventy-one million, nine hundred sixty-three thousand, nine hundred four".