1966845631617 has 6 divisors (see below), whose sum is σ = 2840999245682. Its totient is φ = 1311230421072.

The previous prime is 1966845631607. The next prime is 1966845631657. The reversal of 1966845631617 is 7161365486691.

It is a happy number.

1966845631617 is a `hidden beast` number, since 1 + 9 + 6 + 6 + 8 + 4 + 5 + 6 + 3 + 1 + 617 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1608815728881 + 358029902736 = 1268391^2 + 598356^2 .

It is not a de Polignac number, because 1966845631617 - 2¹⁴ = 1966845615233 is a prime.

It is a super-2 number, since 2×1966845631617² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1966845631607) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 109269201748 + ... + 109269201765.

Almost surely, 2^{1966845631617} is an apocalyptic number.

It is an amenable number.

1966845631617 is a deficient number, since it is larger than the sum of its proper divisors (874153614065).

1966845631617 is a wasteful number, since it uses less digits than its factorization.

1966845631617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218538403519 (or 218538403516 counting only the distinct ones).

The product of its digits is 39191040, while the sum is 63.

The spelling of 1966845631617 in words is "one trillion, nine hundred sixty-six billion, eight hundred forty-five million, six hundred thirty-one thousand, six hundred seventeen".