6656685420 has 192 divisors, whose sum is σ = 23296896000. Its totient is φ = 1379696640.

The previous prime is 6656685389. The next prime is 6656685437. The reversal of 6656685420 is 245866566.

It is a super-2 number, since 2×6656685420² = 88622921561681152800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 6656685420.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2072776 + ... + 2075984.

It is an arithmetic number, because the mean of its divisors is an integer number (121338000).

Almost surely, 2^6656685420 is an apocalyptic number.

6656685420 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 6656685420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11648448000).

6656685420 is an abundant number, since it is smaller than the sum of its proper divisors (16640210580).

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

6656685420 is a wasteful number, since it uses less digits than its factorization.

6656685420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3688 (or 3686 counting only the distinct ones).

The product of its (nonzero) digits is 2073600, while the sum is 48.

The square root of 6656685420 is about 81588.5127943879. The cubic root of 6656685420 is about 1881.1323173442.

It can be divided in two parts, 6656 and 685420, that added together give a triangular number (692076 = T₁₁₇₆).

The spelling of 6656685420 in words is "six billion, six hundred fifty-six million, six hundred eighty-five thousand, four hundred twenty".