521904672 has 72 divisors (see below), whose sum is σ = 1489679100. Its totient is φ = 173322240.

The previous prime is 521904671. The next prime is 521904683. The reversal of 521904672 is 276409125.

521904672 is a `hidden beast` number, since 5 + 2 + 190 + 467 + 2 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 444535056 + 77369616 = 21084^2 + 8796^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (521904671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 77704 + ... + 84152.

Almost surely, 2^521904672 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 521904672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (744839550).

521904672 is an abundant number, since it is smaller than the sum of its proper divisors (967774428).

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

521904672 is a wasteful number, since it uses less digits than its factorization.

521904672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6746 (or 6735 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 521904672 is about 22845.2330257321. The cubic root of 521904672 is about 805.1257712776.

The spelling of 521904672 in words is "five hundred twenty-one million, nine hundred four thousand, six hundred seventy-two".