521763840 has 396 divisors, whose sum is σ = 1986883704. Its totient is φ = 126517248.

The previous prime is 521763839. The next prime is 521763857. The reversal of 521763840 is 48367125.

521763840 is a `hidden beast` number, since 5 + 2 + 17 + 638 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 521763795 and 521763804.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 7787487 + ... + 7787553.

Almost surely, 2^521763840 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 521763840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (993441852).

521763840 is an abundant number, since it is smaller than the sum of its proper divisors (1465119864).

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

521763840 is a wasteful number, since it uses less digits than its factorization.

521763840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124 (or 90 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The square root of 521763840 is about 22842.1505117185. The cubic root of 521763840 is about 805.0533457440.

The spelling of 521763840 in words is "five hundred twenty-one million, seven hundred sixty-three thousand, eight hundred forty".