6566665420 has 72 divisors (see below), whose sum is σ = 16149445200. Its totient is φ = 2236268160.

The previous prime is 6566665409. The next prime is 6566665421. The reversal of 6566665420 is 245666656.

It is not an unprimeable number, because it can be changed into a prime (6566665421) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 123535 + ... + 168505.

It is an arithmetic number, because the mean of its divisors is an integer number (224297850).

Almost surely, 2^6566665420 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 6566665420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8074722600).

6566665420 is an abundant number, since it is smaller than the sum of its proper divisors (9582779780).

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

6566665420 is a wasteful number, since it uses less digits than its factorization.

6566665420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45143 (or 45134 counting only the distinct ones).

The product of its (nonzero) digits is 1555200, while the sum is 46.

The square root of 6566665420 is about 81034.9641821356. The cubic root of 6566665420 is about 1872.6141311050.

The spelling of 6566665420 in words is "six billion, five hundred sixty-six million, six hundred sixty-five thousand, four hundred twenty".