663521040 has 720 divisors, whose sum is σ = 2973559680. Its totient is φ = 129392640.

The previous prime is 663520987. The next prime is 663521051. The reversal of 663521040 is 40125366.

663521040 is a `hidden beast` number, since 6 + 635 + 21 + 0 + 4 + 0 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 663520995 and 663521013.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 16183420 + ... + 16183460.

It is an arithmetic number, because the mean of its divisors is an integer number (4129944).

Almost surely, 2^663521040 is an apocalyptic number.

663521040 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 663521040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1486779840).

663521040 is an abundant number, since it is smaller than the sum of its proper divisors (2310038640).

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

663521040 is a wasteful number, since it uses less digits than its factorization.

663521040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112 (or 90 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 663521040 is about 25758.9021505188. The cubic root of 663521040 is about 872.2043190385.

The spelling of 663521040 in words is "six hundred sixty-three million, five hundred twenty-one thousand, forty".