521552640 has 144 divisors (see below), whose sum is σ = 1903765248. Its totient is φ = 119205888.

The previous prime is 521552609. The next prime is 521552651. The reversal of 521552640 is 46255125.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 521552598 and 521552607.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17179 + ... + 36581.

It is an arithmetic number, because the mean of its divisors is an integer number (13220592).

Almost surely, 2^521552640 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 521552640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (951882624).

521552640 is an abundant number, since it is smaller than the sum of its proper divisors (1382212608).

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

521552640 is a wasteful number, since it uses less digits than its factorization.

521552640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19434 (or 19420 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 30.

The square root of 521552640 is about 22837.5270114783. The cubic root of 521552640 is about 804.9447076975.

The spelling of 521552640 in words is "five hundred twenty-one million, five hundred fifty-two thousand, six hundred forty".