66989729905 has 64 divisors (see below), whose sum is σ = 95701132800. Its totient is φ = 44986233600.

The previous prime is 66989729903. The next prime is 66989729951. The reversal of 66989729905 is 50992798966.

66989729905 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 66989729905 - 2¹ = 66989729903 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66989729903) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 20796195 + ... + 20799415.

It is an arithmetic number, because the mean of its divisors is an integer number (1495330200).

Almost surely, 2^66989729905 is an apocalyptic number.

It is an amenable number.

66989729905 is a deficient number, since it is larger than the sum of its proper divisors (28711402895).

66989729905 is a wasteful number, since it uses less digits than its factorization.

66989729905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3495 (or 3481 counting only the distinct ones).

The product of its (nonzero) digits is 132269760, while the sum is 70.

The spelling of 66989729905 in words is "sixty-six billion, nine hundred eighty-nine million, seven hundred twenty-nine thousand, nine hundred five".