66709019840 has 28 divisors (see below), whose sum is σ = 158850854256. Its totient is φ = 26683607808.

The previous prime is 66709019833. The next prime is 66709019849. The reversal of 66709019840 is 4891090766.

It is not an unprimeable number, because it can be changed into a prime (66709019849) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 104232524 + ... + 104233163.

Almost surely, 2^66709019840 is an apocalyptic number.

It is an amenable number.

66709019840 is an abundant number, since it is smaller than the sum of its proper divisors (92141834416).

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

66709019840 is a wasteful number, since it uses less digits than its factorization.

66709019840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208465704 (or 208465694 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 50.

The spelling of 66709019840 in words is "sixty-six billion, seven hundred nine million, nineteen thousand, eight hundred forty".