6645408 has 192 divisors, whose sum is σ = 23224320. Its totient is φ = 1612800.

The previous prime is 6645391. The next prime is 6645461. The reversal of 6645408 is 8045466.

It is a happy number.

It is a super-2 number, since 2×6645408² = 88322894972928, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 214353 + ... + 214383.

It is an arithmetic number, because the mean of its divisors is an integer number (120960).

Almost surely, 2^6645408 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 6645408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11612160).

6645408 is an abundant number, since it is smaller than the sum of its proper divisors (16578912).

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

6645408 is a wasteful number, since it uses less digits than its factorization.

6645408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91 (or 83 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 33.

The square root of 6645408 is about 2577.8688872788. The cubic root of 6645408 is about 188.0069410445.

The spelling of 6645408 in words is "six million, six hundred forty-five thousand, four hundred eight".