66171721571212 has 24 divisors (see below), whose sum is σ = 116113535874560. Its totient is φ = 32996436858000.

The previous prime is 66171721571201. The next prime is 66171721571231. The reversal of 66171721571212 is 21217512717166.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22261837 + ... + 25058587.

Almost surely, 2^{66171721571212} is an apocalyptic number.

It is an amenable number.

66171721571212 is a deficient number, since it is larger than the sum of its proper divisors (49941814303348).

66171721571212 is a wasteful number, since it uses less digits than its factorization.

66171721571212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2812741 (or 2812739 counting only the distinct ones).

The product of its digits is 493920, while the sum is 49.

The spelling of 66171721571212 in words is "sixty-six trillion, one hundred seventy-one billion, seven hundred twenty-one million, five hundred seventy-one thousand, two hundred twelve".