51660871661666 has 16 divisors (see below), whose sum is σ = 78649651080000. Its totient is φ = 25446104741328.

The previous prime is 51660871661579. The next prime is 51660871661683. The reversal of 51660871661666 is 66616617806615.

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, 445801766 + ... + 445917633.

It is an arithmetic number, because the mean of its divisors is an integer number (4915603192500).

Almost surely, 2^{51660871661666} is an apocalyptic number.

51660871661666 is a deficient number, since it is larger than the sum of its proper divisors (26988779418334).

51660871661666 is a wasteful number, since it uses less digits than its factorization.

51660871661666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 891719833.

The product of its (nonzero) digits is 78382080, while the sum is 65.

The spelling of 51660871661666 in words is "fifty-one trillion, six hundred sixty billion, eight hundred seventy-one million, six hundred sixty-one thousand, six hundred sixty-six".