66449839872 has 72 divisors (see below), whose sum is σ = 190457622544. Its totient is φ = 20446101504.

The previous prime is 66449839849. The next prime is 66449839877. The reversal of 66449839872 is 27893894466.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66449839877) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3317833 + ... + 3337800.

Almost surely, 2^66449839872 is an apocalyptic number.

It is an amenable number.

66449839872 is an abundant number, since it is smaller than the sum of its proper divisors (124007782672).

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

66449839872 is a wasteful number, since it uses less digits than its factorization.

66449839872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6655665 (or 6655651 counting only the distinct ones).

The product of its digits is 125411328, while the sum is 66.

The spelling of 66449839872 in words is "sixty-six billion, four hundred forty-nine million, eight hundred thirty-nine thousand, eight hundred seventy-two".