6645974844920 has 192 divisors, whose sum is σ = 17085325904640. Its totient is φ = 2316025958400.

The previous prime is 6645974844911. The next prime is 6645974844947. The reversal of 6645974844920 is 294484795466.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (68).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 10853330 + ... + 11449310.

It is an arithmetic number, because the mean of its divisors is an integer number (88986072420).

Almost surely, 2^{6645974844920} 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 6645974844920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8542662952320).

6645974844920 is an abundant number, since it is smaller than the sum of its proper divisors (10439351059720).

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

6645974844920 is a wasteful number, since it uses less digits than its factorization.

6645974844920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 596086 (or 596059 counting only the distinct ones).

The product of its (nonzero) digits is 418037760, while the sum is 68.

The spelling of 6645974844920 in words is "six trillion, six hundred forty-five billion, nine hundred seventy-four million, eight hundred forty-four thousand, nine hundred twenty".