66443789997 has 32 divisors (see below), whose sum is σ = 106348220160. Its totient is φ = 40756944960.

The previous prime is 66443789987. The next prime is 66443790011. The reversal of 66443789997 is 79998734466.

66443789997 is a `hidden beast` number, since 6 + 6 + 443 + 7 + 8 + 99 + 97 = 666.

It is not a de Polignac number, because 66443789997 - 2⁴ = 66443789981 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66443789947) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 195178 + ... + 413499.

It is an arithmetic number, because the mean of its divisors is an integer number (3323381880).

Almost surely, 2^66443789997 is an apocalyptic number.

It is an amenable number.

66443789997 is a deficient number, since it is larger than the sum of its proper divisors (39904430163).

66443789997 is a wasteful number, since it uses less digits than its factorization.

66443789997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 609010 (or 609004 counting only the distinct ones).

The product of its digits is 493807104, while the sum is 72.

The spelling of 66443789997 in words is "sixty-six billion, four hundred forty-three million, seven hundred eighty-nine thousand, nine hundred ninety-seven".