663636680 has 64 divisors (see below), whose sum is σ = 1712206080. Its totient is φ = 226771200.

The previous prime is 663636671. The next prime is 663636689. The reversal of 663636680 is 86636366.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (663636671) and next prime (663636689).

It is not an unprimeable number, because it can be changed into a prime (663636689) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 83270 + ... + 90890.

It is an arithmetic number, because the mean of its divisors is an integer number (26753220).

Almost surely, 2^663636680 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 663636680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (856103040).

663636680 is an abundant number, since it is smaller than the sum of its proper divisors (1048569400).

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

663636680 is a wasteful number, since it uses less digits than its factorization.

663636680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7950 (or 7946 counting only the distinct ones).

The product of its (nonzero) digits is 559872, while the sum is 44.

The square root of 663636680 is about 25761.1467136073. The cubic root of 663636680 is about 872.2549860319.

The spelling of 663636680 in words is "six hundred sixty-three million, six hundred thirty-six thousand, six hundred eighty".