663310884721 has 9 divisors (see below), whose sum is σ = 670920873483. Its totient is φ = 655786282800.

The previous prime is 663310884689. The next prime is 663310884751. The reversal of 663310884721 is 127488013366.

The square root of 663310884721 is 814439.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 127369758321 + 535941126400 = 356889^2 + 732080^2 .

It is not a de Polignac number, because 663310884721 - 2⁵ = 663310884689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (663310884751) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 72480496 + ... + 72489646.

Almost surely, 2^663310884721 is an apocalyptic number.

663310884721 is the 814439-th square number.

663310884721 is the 407220-th centered octagonal number.

It is an amenable number.

663310884721 is a deficient number, since it is larger than the sum of its proper divisors (7609988762).

663310884721 is an frugal number, since it uses more digits than its factorization.

663310884721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18480 (or 9240 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 49.

Multiplying 663310884721 by its sum of digits (49), we get a square (32502233351329 = 5701073²).

The spelling of 663310884721 in words is "six hundred sixty-three billion, three hundred ten million, eight hundred eighty-four thousand, seven hundred twenty-one".