166490666681 has 8 divisors (see below), whose sum is σ = 168051565440. Its totient is φ = 164930376528.

The previous prime is 166490666663. The next prime is 166490666689. The reversal of 166490666681 is 186666094661.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 166490666681 - 2¹⁰ = 166490665657 is a prime.

It is a super-2 number, since 2×166490666681² (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 166490666681.

It is not an unprimeable number, because it can be changed into a prime (166490666689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 407120 + ... + 706206.

It is an arithmetic number, because the mean of its divisors is an integer number (21006445680).

Almost surely, 2^166490666681 is an apocalyptic number.

It is an amenable number.

166490666681 is a deficient number, since it is larger than the sum of its proper divisors (1560898759).

166490666681 is a wasteful number, since it uses less digits than its factorization.

166490666681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 304303.

The product of its (nonzero) digits is 13436928, while the sum is 59.

The spelling of 166490666681 in words is "one hundred sixty-six billion, four hundred ninety million, six hundred sixty-six thousand, six hundred eighty-one".