66402220 has 24 divisors (see below), whose sum is σ = 139812624. Its totient is φ = 26490816.

The previous prime is 66402209. The next prime is 66402239. The reversal of 66402220 is 2220466.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 66402191 and 66402200.

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 7 ways as a sum of consecutive naturals, for example, 3759 + ... + 12121.

It is an arithmetic number, because the mean of its divisors is an integer number (5825526).

Almost surely, 2^66402220 is an apocalyptic number.

It is an amenable number.

66402220 is an abundant number, since it is smaller than the sum of its proper divisors (73410404).

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

66402220 is a wasteful number, since it uses less digits than its factorization.

66402220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8769 (or 8767 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 66402220 is about 8148.7557332393. The cubic root of 66402220 is about 404.9432832226.

Adding to 66402220 its reverse (2220466), we get a palindrome (68622686).

The spelling of 66402220 in words is "sixty-six million, four hundred two thousand, two hundred twenty".