66609774 has 144 divisors (see below), whose sum is σ = 192707424. Its totient is φ = 16220160.

The previous prime is 66609769. The next prime is 66609779. The reversal of 66609774 is 47790666.

It is an interprime number because it is at equal distance from previous prime (66609769) and next prime (66609779).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66609779) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 259054 + ... + 259310.

It is an arithmetic number, because the mean of its divisors is an integer number (1338246).

Almost surely, 2^66609774 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66609774, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96353712).

66609774 is an abundant number, since it is smaller than the sum of its proper divisors (126097650).

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

66609774 is a wasteful number, since it uses less digits than its factorization.

66609774 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 311 (or 297 counting only the distinct ones).

The product of its (nonzero) digits is 381024, while the sum is 45.

The square root of 66609774 is about 8161.4811155819. The cubic root of 66609774 is about 405.3647559812.

The spelling of 66609774 in words is "sixty-six million, six hundred nine thousand, seven hundred seventy-four".