663866580049920 has 840 divisors, whose sum is σ = 2577096275300316. Its totient is φ = 163413173993472.

The previous prime is 663866580049919. The next prime is 663866580049921. The reversal of 663866580049920 is 29940085668366.

663866580049920 is a `hidden beast` number, since 6 + 6 + 3 + 8 + 66 + 58 + 0 + 0 + 499 + 20 = 666.

It is an interprime number because it is at equal distance from previous prime (663866580049919) and next prime (663866580049921).

It can be written as a sum of positive squares in 6 ways, for example, as 681298366464 + 663185281683456 = 825408^2 + 25752384^2 .

It is a super-2 number, since 2×663866580049920² (a number of 30 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is not an unprimeable number, because it can be changed into a prime (663866580049921) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 560109444 + ... + 561293436.

Almost surely, 2^{663866580049920} is an apocalyptic number.

663866580049920 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 663866580049920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1288548137650158).

663866580049920 is an abundant number, since it is smaller than the sum of its proper divisors (1913229695250396).

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

663866580049920 is a wasteful number, since it uses less digits than its factorization.

663866580049920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1184062 (or 1184016 counting only the distinct ones).

The product of its (nonzero) digits is 806215680, while the sum is 72.

The spelling of 663866580049920 in words is "six hundred sixty-three trillion, eight hundred sixty-six billion, five hundred eighty million, forty-nine thousand, nine hundred twenty".