166766873641 has 9 divisors (see below), whose sum is σ = 170753345751. Its totient is φ = 162871422672.

The previous prime is 166766873617. The next prime is 166766873653. The reversal of 166766873641 is 146378667661.

The square root of 166766873641 is 408371.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 7808373225 + 158958500416 = 88365^2 + 398696^2 .

It is not a de Polignac number, because 166766873641 - 2¹³ = 166766865449 is a prime.

It is a super-2 number, since 2×166766873641² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 166766873641.

It is not an unprimeable number, because it can be changed into a prime (166766873671) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 17555205 + ... + 17564701.

Almost surely, 2^166766873641 is an apocalyptic number.

166766873641 is the 408371-st square number.

166766873641 is the 204186-th centered octagonal number.

It is an amenable number.

166766873641 is a deficient number, since it is larger than the sum of its proper divisors (3986472110).

166766873641 is an frugal number, since it uses more digits than its factorization.

166766873641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19080 (or 9540 counting only the distinct ones).

The product of its digits is 36578304, while the sum is 61.

The spelling of 166766873641 in words is "one hundred sixty-six billion, seven hundred sixty-six million, eight hundred seventy-three thousand, six hundred forty-one".