66172224 has 56 divisors (see below), whose sum is σ = 176771808. Its totient is φ = 21844480.

The previous prime is 66172189. The next prime is 66172261. The reversal of 66172224 is 42227166.

66172224 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 66172191 and 66172200.

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 7 ways as a sum of consecutive naturals, for example, 18934 + ... + 22154.

Almost surely, 2^66172224 is an apocalyptic number.

66172224 is a gapful number since it is divisible by the number (64) 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 66172224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88385904).

66172224 is an abundant number, since it is smaller than the sum of its proper divisors (110599584).

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

66172224 is a wasteful number, since it uses less digits than its factorization.

66172224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3343 (or 3333 counting only the distinct ones).

The product of its digits is 8064, while the sum is 30.

The square root of 66172224 is about 8134.6311532853. The cubic root of 66172224 is about 404.4752111558.

The spelling of 66172224 in words is "sixty-six million, one hundred seventy-two thousand, two hundred twenty-four".