66816222 has 96 divisors (see below), whose sum is σ = 161270784. Its totient is φ = 18278400.

The previous prime is 66816221. The next prime is 66816223. The reversal of 66816222 is 22261866.

It is an interprime number because it is at equal distance from previous prime (66816221) and next prime (66816223).

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66816221) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 591238 + ... + 591350.

It is an arithmetic number, because the mean of its divisors is an integer number (1679904).

Almost surely, 2^66816222 is an apocalyptic number.

66816222 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 66816222, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80635392).

66816222 is an abundant number, since it is smaller than the sum of its proper divisors (94454562).

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

66816222 is a wasteful number, since it uses less digits than its factorization.

66816222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194 (or 177 counting only the distinct ones).

The product of its digits is 13824, while the sum is 33.

The square root of 66816222 is about 8174.1190351010. The cubic root of 66816222 is about 405.7831151704.

The spelling of 66816222 in words is "sixty-six million, eight hundred sixteen thousand, two hundred twenty-two".