521938337209 has 27 divisors (see below), whose sum is σ = 552851242447. Its totient is φ = 492712946000.

The previous prime is 521938337203. The next prime is 521938337237. The reversal of 521938337209 is 902733839125.

The square root of 521938337209 is 722453.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 501472173609 + 20466163600 = 708147^2 + 143060^2 .

It is not a de Polignac number, because 521938337209 - 2³ = 521938337201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (521938337201) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1678258164 + ... + 1678258474.

Almost surely, 2^521938337209 is an apocalyptic number.

521938337209 is the 722453-rd square number.

521938337209 is the 361227-th centered octagonal number.

It is an amenable number.

521938337209 is a deficient number, since it is larger than the sum of its proper divisors (30912905238).

521938337209 is an frugal number, since it uses more digits than its factorization.

521938337209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 870 (or 435 counting only the distinct ones).

The product of its (nonzero) digits is 2449440, while the sum is 52.

The spelling of 521938337209 in words is "five hundred twenty-one billion, nine hundred thirty-eight million, three hundred thirty-seven thousand, two hundred nine".