6645820416 has 176 divisors, whose sum is σ = 18519290880. Its totient is φ = 2116730880.

The previous prime is 6645820403. The next prime is 6645820427. The reversal of 6645820416 is 6140285466.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6705681 + ... + 6706671.

Almost surely, 2^6645820416 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 6645820416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9259645440).

6645820416 is an abundant number, since it is smaller than the sum of its proper divisors (11873470464).

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

6645820416 is a wasteful number, since it uses less digits than its factorization.

6645820416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1110 (or 1092 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 42.

The square root of 6645820416 is about 81521.9014498558. The cubic root of 6645820416 is about 1880.1083021960.

The spelling of 6645820416 in words is "six billion, six hundred forty-five million, eight hundred twenty thousand, four hundred sixteen".