66071220 has 48 divisors (see below), whose sum is σ = 189309120. Its totient is φ = 17208576.

The previous prime is 66071191. The next prime is 66071267. The reversal of 66071220 is 2217066.

It is a happy number.

66071220 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×66071220² = 8730812224576800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10225 + ... + 15384.

It is an arithmetic number, because the mean of its divisors is an integer number (3943940).

Almost surely, 2^66071220 is an apocalyptic number.

66071220 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66071220 is an abundant number, since it is smaller than the sum of its proper divisors (123237900).

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

66071220 is a wasteful number, since it uses less digits than its factorization.

66071220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25664 (or 25662 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 66071220 is about 8128.4205107758. The cubic root of 66071220 is about 404.2693119861.

Adding to 66071220 its reverse (2217066), we get a palindrome (68288286).

The spelling of 66071220 in words is "sixty-six million, seventy-one thousand, two hundred twenty".