521565066 has 96 divisors (see below), whose sum is σ = 1362261888. Its totient is φ = 142264320.

The previous prime is 521565053. The next prime is 521565073. The reversal of 521565066 is 660565125.

It is a happy number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 521565066.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 74050 + ... + 80786.

It is an arithmetic number, because the mean of its divisors is an integer number (14190228).

Almost surely, 2^521565066 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 521565066, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (681130944).

521565066 is an abundant number, since it is smaller than the sum of its proper divisors (840696822).

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

521565066 is a wasteful number, since it uses less digits than its factorization.

521565066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6796 (or 6793 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 36.

The square root of 521565066 is about 22837.7990620813. The cubic root of 521565066 is about 804.9511002535.

The spelling of 521565066 in words is "five hundred twenty-one million, five hundred sixty-five thousand, sixty-six".