66813424 has 40 divisors (see below), whose sum is σ = 136935680. Its totient is φ = 31492800.

The previous prime is 66813389. The next prime is 66813427. The reversal of 66813424 is 42431866.

It is a super-3 number, since 3×66813424³ (a number of 24 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66813424.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66813427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81979 + ... + 82789.

It is an arithmetic number, because the mean of its divisors is an integer number (3423392).

Almost surely, 2^66813424 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66813424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68467840).

66813424 is an abundant number, since it is smaller than the sum of its proper divisors (70122256).

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

66813424 is a wasteful number, since it uses less digits than its factorization.

66813424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1109 (or 1103 counting only the distinct ones).

The product of its digits is 27648, while the sum is 34.

The square root of 66813424 is about 8173.9478833670. The cubic root of 66813424 is about 405.7774508922. Note that the first 3 decimals are identical.

The spelling of 66813424 in words is "sixty-six million, eight hundred thirteen thousand, four hundred twenty-four".