501686640 has 720 divisors, whose sum is σ = 2265569280. Its totient is φ = 97044480.

The previous prime is 501686629. The next prime is 501686641. The reversal of 501686640 is 46686105.

501686640 is a `hidden beast` number, since 5 + 0 + 1 + 6 + 8 + 6 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a super-3 number, since 3×501686640³ (a number of 27 digits) contains 333 as substring.

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 = 501686595 and 501686604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (501686641) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 16183425 + ... + 16183455.

It is an arithmetic number, because the mean of its divisors is an integer number (3146624).

Almost surely, 2^501686640 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 501686640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1132784640).

501686640 is an abundant number, since it is smaller than the sum of its proper divisors (1763882640).

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

501686640 is a wasteful number, since it uses less digits than its factorization.

501686640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102 (or 80 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 501686640 is about 22398.3624401428. The cubic root of 501686640 is about 794.5919823936.

The spelling of 501686640 in words is "five hundred one million, six hundred eighty-six thousand, six hundred forty".