66760720 has 80 divisors (see below), whose sum is σ = 174488832. Its totient is φ = 23569920.

The previous prime is 66760703. The next prime is 66760721. The reversal of 66760720 is 2706766.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (66760721) 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, 22525 + ... + 25315.

Almost surely, 2^66760720 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 66760720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87244416).

66760720 is an abundant number, since it is smaller than the sum of its proper divisors (107728112).

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

66760720 is a wasteful number, since it uses less digits than its factorization.

66760720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2840 (or 2834 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 34.

The square root of 66760720 is about 8170.7233461916. The cubic root of 66760720 is about 405.6707272268.

The spelling of 66760720 in words is "sixty-six million, seven hundred sixty thousand, seven hundred twenty".