521665248 has 96 divisors (see below), whose sum is σ = 1484130816. Its totient is φ = 159487488.

The previous prime is 521665219. The next prime is 521665279. The reversal of 521665248 is 842566125.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 207165 + ... + 209667.

It is an arithmetic number, because the mean of its divisors is an integer number (15459696).

Almost surely, 2^521665248 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 521665248, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (742065408).

521665248 is an abundant number, since it is smaller than the sum of its proper divisors (962465568).

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

521665248 is a wasteful number, since it uses less digits than its factorization.

521665248 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2696 (or 2688 counting only the distinct ones).

The product of its digits is 115200, while the sum is 39.

The square root of 521665248 is about 22839.9922942194. The cubic root of 521665248 is about 805.0026351778.

The spelling of 521665248 in words is "five hundred twenty-one million, six hundred sixty-five thousand, two hundred forty-eight".