663911553816 has 288 divisors, whose sum is σ = 2239110881280. Its totient is φ = 183569198400.

The previous prime is 663911553791. The next prime is 663911553829. The reversal of 663911553816 is 618355119366.

663911553816 is a `hidden beast` number, since 6 + 6 + 3 + 9 + 1 + 1 + 553 + 81 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2840521 + ... + 3065351.

It is an arithmetic number, because the mean of its divisors is an integer number (7774690560).

Almost surely, 2^663911553816 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 663911553816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1119555440640).

663911553816 is an abundant number, since it is smaller than the sum of its proper divisors (1575199327464).

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

663911553816 is a wasteful number, since it uses less digits than its factorization.

663911553816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224897 (or 224874 counting only the distinct ones).

The product of its digits is 3499200, while the sum is 54.

The spelling of 663911553816 in words is "six hundred sixty-three billion, nine hundred eleven million, five hundred fifty-three thousand, eight hundred sixteen".