521861208064 has 384 divisors, whose sum is σ = 1260971712000. Its totient is φ = 215724687360.

The previous prime is 521861208013. The next prime is 521861208107. The reversal of 521861208064 is 460802168125.

It is a self number, because there is not a number n which added to its sum of digits gives 521861208064.

It is a congruent number.

It is an unprimeable 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 in 31 ways as a sum of consecutive naturals, for example, 3983673279 + ... + 3983673409.

It is an arithmetic number, because the mean of its divisors is an integer number (3283780500).

Almost surely, 2^521861208064 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 521861208064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (630485856000).

521861208064 is an abundant number, since it is smaller than the sum of its proper divisors (739110503936).

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

521861208064 is a wasteful number, since it uses less digits than its factorization.

521861208064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 334 (or 300 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 43.

The spelling of 521861208064 in words is "five hundred twenty-one billion, eight hundred sixty-one million, two hundred eight thousand, sixty-four".