66065220 has 120 divisors (see below), whose sum is σ = 223262424. Its totient is φ = 16257024.

The previous prime is 66065203. The next prime is 66065231. The reversal of 66065220 is 2256066.

66065220 is a `hidden beast` number, since 6 + 6 + 0 + 652 + 2 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 15256836 + 50808384 = 3906^2 + 7128^2 .

It is a super-2 number, since 2×66065220² = 8729226587296800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 19492 + ... + 22628.

Almost surely, 2^66065220 is an apocalyptic number.

66065220 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 66065220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111631212).

66065220 is an abundant number, since it is smaller than the sum of its proper divisors (157197204).

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

66065220 is a wasteful number, since it uses less digits than its factorization.

66065220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3171 (or 3160 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 66065220 is about 8128.0514270027. The cubic root of 66065220 is about 404.2570742357.

The spelling of 66065220 in words is "sixty-six million, sixty-five thousand, two hundred twenty".