521631648 has 72 divisors (see below), whose sum is σ = 1485741348. Its totient is φ = 173601792.

The previous prime is 521631641. The next prime is 521631673. The reversal of 521631648 is 846136125.

It is a happy number.

521631648 is a `hidden beast` number, since 5 + 2 + 1 + 6 + 3 + 1 + 648 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 504092304 + 17539344 = 22452^2 + 4188^2 .

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 (521631641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 268890 + ... + 270822.

Almost surely, 2^521631648 is an apocalyptic number.

It is an amenable number.

521631648 is an abundant number, since it is smaller than the sum of its proper divisors (964109700).

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

521631648 is a wasteful number, since it uses less digits than its factorization.

521631648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2886 (or 2875 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 521631648 is about 22839.2567304630. The cubic root of 521631648 is about 804.9853516360.

It can be divided in two parts, 5216 and 31648, that added together give a square (36864 = 192²).

The spelling of 521631648 in words is "five hundred twenty-one million, six hundred thirty-one thousand, six hundred forty-eight".