6651840 has 168 divisors, whose sum is σ = 23426928. Its totient is φ = 1597440.

The previous prime is 6651839. The next prime is 6651847. The reversal of 6651840 is 481566.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 6651798 and 6651807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6651847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 162220 + ... + 162260.

It is an arithmetic number, because the mean of its divisors is an integer number (139446).

Almost surely, 2^6651840 is an apocalyptic number.

6651840 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 6651840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11713464).

6651840 is an abundant number, since it is smaller than the sum of its proper divisors (16775088).

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

6651840 is a wasteful number, since it uses less digits than its factorization.

6651840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87 (or 64 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 6651840 is about 2579.1161276685. The cubic root of 6651840 is about 188.0675779390.

The spelling of 6651840 in words is "six million, six hundred fifty-one thousand, eight hundred forty".