521908 has 6 divisors (see below), whose sum is σ = 913346. Its totient is φ = 260952.

The previous prime is 521903. The next prime is 521923. The reversal of 521908 is 809125.

It can be written as a sum of positive squares in only one way, i.e., 338724 + 183184 = 582^2 + 428^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521903) by changing a digit.

521908 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 as a sum of consecutive naturals, namely, 65235 + ... + 65242.

2⁵²¹⁹⁰⁸ is an apocalyptic number.

It is an amenable number.

521908 is a deficient number, since it is larger than the sum of its proper divisors (391438).

521908 is a wasteful number, since it uses less digits than its factorization.

521908 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130481 (or 130479 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 521908 is about 722.4320037208. The cubic root of 521908 is about 80.5127482607.

The spelling of 521908 in words is "five hundred twenty-one thousand, nine hundred eight".