669646541340 has 432 divisors, whose sum is σ = 2523437908992. Its totient is φ = 140704929792.

The previous prime is 669646541321. The next prime is 669646541341. The reversal of 669646541340 is 43145646966.

669646541340 is a `hidden beast` number, since 6 + 6 + 9 + 64 + 6 + 541 + 34 + 0 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669646541341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 15636637 + ... + 15679403.

It is an arithmetic number, because the mean of its divisors is an integer number (5841291456).

Almost surely, 2^669646541340 is an apocalyptic number.

669646541340 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 669646541340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1261718954496).

669646541340 is an abundant number, since it is smaller than the sum of its proper divisors (1853791367652).

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

669646541340 is a wasteful number, since it uses less digits than its factorization.

669646541340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42866 (or 42844 counting only the distinct ones).

The product of its (nonzero) digits is 11197440, while the sum is 54.

The spelling of 669646541340 in words is "six hundred sixty-nine billion, six hundred forty-six million, five hundred forty-one thousand, three hundred forty".