668824645489 has 243 divisors, whose sum is σ = 1000583129259. Its totient is φ = 445154149440.

The previous prime is 668824645409. The next prime is 668824645537. The reversal of 668824645489 is 984546428866.

The square root of 668824645489 is 817817.

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., 98938557025 + 569886088464 = 314545^2 + 754908^2 .

It is not a de Polignac number, because 668824645489 - 2¹³ = 668824637297 is a prime.

It is not an unprimeable number, because it can be changed into a prime (668824645409) by changing a digit.

It is a polite number, since it can be written in 242 ways as a sum of consecutive naturals, for example, 15554061502 + ... + 15554061544.

Almost surely, 2^668824645489 is an apocalyptic number.

668824645489 is the 817817-th square number.

668824645489 is the 408909-th centered octagonal number.

It is an amenable number.

668824645489 is a deficient number, since it is larger than the sum of its proper divisors (331758483770).

668824645489 is a wasteful number, since it uses less digits than its factorization.

668824645489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 186 (or 93 counting only the distinct ones).

The product of its digits is 637009920, while the sum is 70.

The spelling of 668824645489 in words is "six hundred sixty-eight billion, eight hundred twenty-four million, six hundred forty-five thousand, four hundred eighty-nine".