66709280 has 96 divisors (see below), whose sum is σ = 177992640. Its totient is φ = 23403520.

The previous prime is 66709267. The next prime is 66709283. The reversal of 66709280 is 8290766.

It is not an unprimeable number, because it can be changed into a prime (66709283) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50387 + ... + 51693.

It is an arithmetic number, because the mean of its divisors is an integer number (1854090).

Almost surely, 2^66709280 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 66709280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88996320).

66709280 is an abundant number, since it is smaller than the sum of its proper divisors (111283360).

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

66709280 is a wasteful number, since it uses less digits than its factorization.

66709280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1362 (or 1354 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 38.

The square root of 66709280 is about 8167.5749154813. The cubic root of 66709280 is about 405.5665089374.

The spelling of 66709280 in words is "sixty-six million, seven hundred nine thousand, two hundred eighty".