66800028309 has 16 divisors (see below), whose sum is σ = 102691324032. Its totient is φ = 37833643008.

The previous prime is 66800028283. The next prime is 66800028331. The reversal of 66800028309 is 90382000866.

It is not a de Polignac number, because 66800028309 - 2⁹ = 66800027797 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66800028359) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14072644 + ... + 14077389.

It is an arithmetic number, because the mean of its divisors is an integer number (6418207752).

Almost surely, 2^66800028309 is an apocalyptic number.

It is an amenable number.

66800028309 is a deficient number, since it is larger than the sum of its proper divisors (35891295723).

66800028309 is a wasteful number, since it uses less digits than its factorization.

66800028309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28150156.

The product of its (nonzero) digits is 124416, while the sum is 42.

The spelling of 66800028309 in words is "sixty-six billion, eight hundred million, twenty-eight thousand, three hundred nine".