663936780 has 144 divisors (see below), whose sum is σ = 2063414304. Its totient is φ = 159344640.

The previous prime is 663936761. The next prime is 663936781. The reversal of 663936780 is 87639366.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (663936781) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 414942 + ... + 416538.

It is an arithmetic number, because the mean of its divisors is an integer number (14329266).

Almost surely, 2^663936780 is an apocalyptic number.

663936780 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 663936780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1031707152).

663936780 is an abundant number, since it is smaller than the sum of its proper divisors (1399477524).

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

663936780 is a wasteful number, since it uses less digits than its factorization.

663936780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1676 (or 1661 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 48.

The square root of 663936780 is about 25766.9707183441. The cubic root of 663936780 is about 872.3864456504.

The spelling of 663936780 in words is "six hundred sixty-three million, nine hundred thirty-six thousand, seven hundred eighty".