6420660066 has 24 divisors (see below), whose sum is σ = 13991849820. Its totient is φ = 2127847776.

The previous prime is 6420660053. The next prime is 6420660067. The reversal of 6420660066 is 6600660246.

6420660066 is a `hidden beast` number, since 6 + 42 + 0 + 6 + 600 + 6 + 6 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 6303566025 + 117094041 = 79395^2 + 10821^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 6420660066.

It is not an unprimeable number, because it can be changed into a prime (6420660067) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1027821 + ... + 1034048.

Almost surely, 2^6420660066 is an apocalyptic number.

6420660066 is an abundant number, since it is smaller than the sum of its proper divisors (7571189754).

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

6420660066 is a wasteful number, since it uses less digits than its factorization.

6420660066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2062050 (or 2062047 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 36.

The square root of 6420660066 is about 80129.0213717851. The cubic root of 6420660066 is about 1858.6312111199.

The spelling of 6420660066 in words is "six billion, four hundred twenty million, six hundred sixty thousand, sixty-six".