66837966973866 has 36 divisors (see below), whose sum is σ = 159177472316226. Its totient is φ = 20253929385360.

The previous prime is 66837966973831. The next prime is 66837966973871.

It is a happy number.

66837966973866 is a `hidden beast` number, since 6 + 6 + 8 + 379 + 66 + 97 + 38 + 66 = 666.

66837966973866 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in only one way, i.e., 66753883793025 + 84083180841 = 8170305^2 + 289971^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 15343883721 + ... + 15343888076.

Almost surely, 2^{66837966973866} is an apocalyptic number.

66837966973866 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

66837966973866 is an abundant number, since it is smaller than the sum of its proper divisors (92339505342360).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66837966973866 is a wasteful number, since it uses less digits than its factorization.

66837966973866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30687771827 (or 30687771813 counting only the distinct ones).

The product of its digits is 106662334464, while the sum is 90.

The spelling of 66837966973866 in words is "sixty-six trillion, eight hundred thirty-seven billion, nine hundred sixty-six million, nine hundred seventy-three thousand, eight hundred sixty-six".