66128878634 has 32 divisors (see below), whose sum is σ = 122375594880. Its totient is φ = 26098408512.

The previous prime is 66128878633. The next prime is 66128878637. The reversal of 66128878634 is 43687882166.

It is a happy number.

It is a Smith number, since the sum of its digits (59) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (66128878631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 357329 + ... + 509844.

It is an arithmetic number, because the mean of its divisors is an integer number (3824237340).

Almost surely, 2^66128878634 is an apocalyptic number.

66128878634 is a deficient number, since it is larger than the sum of its proper divisors (56246716246).

66128878634 is a wasteful number, since it uses less digits than its factorization.

66128878634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 867614.

The product of its digits is 18579456, while the sum is 59.

The spelling of 66128878634 in words is "sixty-six billion, one hundred twenty-eight million, eight hundred seventy-eight thousand, six hundred thirty-four".