66420288 has 126 divisors (see below), whose sum is σ = 209482182. Its totient is φ = 20106240.

The previous prime is 66420283. The next prime is 66420293. The reversal of 66420288 is 88202466.

66420288 is a `hidden beast` number, since 6 + 642 + 0 + 2 + 8 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (66420283) and next prime (66420293).

It can be written as a sum of positive squares in only one way, i.e., 54641664 + 11778624 = 7392^2 + 3432^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (66420281) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 69220 + ... + 70172.

It is an arithmetic number, because the mean of its divisors is an integer number (1662557).

Almost surely, 2^66420288 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 66420288, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104741091).

66420288 is an abundant number, since it is smaller than the sum of its proper divisors (143061894).

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

66420288 is a wasteful number, since it uses less digits than its factorization.

66420288 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 993 (or 969 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 36.

The square root of 66420288 is about 8149.8642933487. The cubic root of 66420288 is about 404.9800081581.

The spelling of 66420288 in words is "sixty-six million, four hundred twenty thousand, two hundred eighty-eight".