521255040 has 128 divisors (see below), whose sum is σ = 1684713600. Its totient is φ = 137060352.

The previous prime is 521255039. The next prime is 521255047. The reversal of 521255040 is 40552125.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 521255040.

It is not an unprimeable number, because it can be changed into a prime (521255047) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 138301 + ... + 142019.

It is an arithmetic number, because the mean of its divisors is an integer number (13161825).

Almost surely, 2^521255040 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 521255040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (842356800).

521255040 is an abundant number, since it is smaller than the sum of its proper divisors (1163458560).

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

521255040 is a wasteful number, since it uses less digits than its factorization.

521255040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3814 (or 3802 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 24.

The square root of 521255040 is about 22831.0104901207. The cubic root of 521255040 is about 804.7915770231.

The spelling of 521255040 in words is "five hundred twenty-one million, two hundred fifty-five thousand, forty".