66971760 has 80 divisors (see below), whose sum is σ = 208941984. Its totient is φ = 17744896.

The previous prime is 66971741. The next prime is 66971761. The reversal of 66971760 is 6717966.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66971761) 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, 40714 + ... + 42326.

Almost surely, 2^66971760 is an apocalyptic number.

66971760 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66971760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104470992).

66971760 is an abundant number, since it is smaller than the sum of its proper divisors (141970224).

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

66971760 is a wasteful number, since it uses less digits than its factorization.

66971760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1802 (or 1796 counting only the distinct ones).

The product of its (nonzero) digits is 95256, while the sum is 42.

The square root of 66971760 is about 8183.6275575077. The cubic root of 66971760 is about 406.0977382849.

The spelling of 66971760 in words is "sixty-six million, nine hundred seventy-one thousand, seven hundred sixty".