521963654520 has 768 divisors, whose sum is σ = 2072304622080. Its totient is φ = 103909478400.

The previous prime is 521963654519. The next prime is 521963654627. The reversal of 521963654520 is 25456369125.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 521963654520.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 147403950 + ... + 147407490.

It is an arithmetic number, because the mean of its divisors is an integer number (2698313310).

Almost surely, 2^521963654520 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 521963654520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1036152311040).

521963654520 is an abundant number, since it is smaller than the sum of its proper divisors (1550340967560).

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

521963654520 is a wasteful number, since it uses less digits than its factorization.

521963654520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3676 (or 3665 counting only the distinct ones).

The product of its (nonzero) digits is 1944000, while the sum is 48.

The spelling of 521963654520 in words is "five hundred twenty-one billion, nine hundred sixty-three million, six hundred fifty-four thousand, five hundred twenty".