1066166606221 has 8 divisors (see below), whose sum is σ = 1066559288504. Its totient is φ = 1065773998080.

The previous prime is 1066166606209. The next prime is 1066166606243. The reversal of 1066166606221 is 1226066616601.

It can be written as a sum of positive squares in 4 ways, for example, as 532733572996 + 533433033225 = 729886^2 + 730365^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1066166606221 is a prime.

It is a super-2 number, since 2×1066166606221² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1066166606201) 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, 52373581 + ... + 52393933.

It is an arithmetic number, because the mean of its divisors is an integer number (133319911063).

Almost surely, 2^{1066166606221} is an apocalyptic number.

It is an amenable number.

1066166606221 is a deficient number, since it is larger than the sum of its proper divisors (392682283).

1066166606221 is a wasteful number, since it uses less digits than its factorization.

1066166606221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37071.

The product of its (nonzero) digits is 186624, while the sum is 43.

The spelling of 1066166606221 in words is "one trillion, sixty-six billion, one hundred sixty-six million, six hundred six thousand, two hundred twenty-one".