66709224 has 128 divisors (see below), whose sum is σ = 201916800. Its totient is φ = 20321280.

The previous prime is 66709213. The next prime is 66709231. The reversal of 66709224 is 42290766.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 135619 + ... + 136109.

It is an arithmetic number, because the mean of its divisors is an integer number (1577475).

Almost surely, 2^66709224 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 66709224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100958400).

66709224 is an abundant number, since it is smaller than the sum of its proper divisors (135207576).

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

66709224 is a wasteful number, since it uses less digits than its factorization.

66709224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 560 (or 550 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 36.

The square root of 66709224 is about 8167.5714872905. The cubic root of 66709224 is about 405.5663954512.

The spelling of 66709224 in words is "sixty-six million, seven hundred nine thousand, two hundred twenty-four".