521808634 has 8 divisors (see below), whose sum is σ = 784017108. Its totient is φ = 260469600.

The previous prime is 521808631. The next prime is 521808643. The reversal of 521808634 is 436808125.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 499388409 + 22420225 = 22347^2 + 4735^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 521808593 and 521808602.

It is not an unprimeable number, because it can be changed into a prime (521808631) 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 3 ways as a sum of consecutive naturals, for example, 215857 + ... + 218260.

Almost surely, 2^521808634 is an apocalyptic number.

521808634 is a deficient number, since it is larger than the sum of its proper divisors (262208474).

521808634 is a wasteful number, since it uses less digits than its factorization.

521808634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 434720.

The product of its (nonzero) digits is 46080, while the sum is 37.

The square root of 521808634 is about 22843.1310025574. The cubic root of 521808634 is about 805.0763833234.

The spelling of 521808634 in words is "five hundred twenty-one million, eight hundred eight thousand, six hundred thirty-four".