669644807440 has 240 divisors, whose sum is σ = 1834113345840. Its totient is φ = 226684846080.

The previous prime is 669644807423. The next prime is 669644807443. The reversal of 669644807440 is 44708446966.

It can be written as a sum of positive squares in 8 ways, for example, as 71039307024 + 598605500416 = 266532^2 + 773696^2 .

It is not an unprimeable number, because it can be changed into a prime (669644807443) 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, 460869754 + ... + 460871206.

It is an arithmetic number, because the mean of its divisors is an integer number (7642138941).

Almost surely, 2^669644807440 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 669644807440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (917056672920).

669644807440 is an abundant number, since it is smaller than the sum of its proper divisors (1164468538400).

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

669644807440 is a wasteful number, since it uses less digits than its factorization.

669644807440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2890 (or 2877 counting only the distinct ones).

The product of its (nonzero) digits is 27869184, while the sum is 58.

The spelling of 669644807440 in words is "six hundred sixty-nine billion, six hundred forty-four million, eight hundred seven thousand, four hundred forty".