66551166 has 64 divisors (see below), whose sum is σ = 162489600. Its totient is φ = 20023200.

The previous prime is 66551137. The next prime is 66551207. The reversal of 66551166 is 66115566.

It is a zygodrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 66551166.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 107205 + ... + 107823.

It is an arithmetic number, because the mean of its divisors is an integer number (2538900).

Almost surely, 2^66551166 is an apocalyptic number.

66551166 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 66551166, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81244800).

66551166 is an abundant number, since it is smaller than the sum of its proper divisors (95938434).

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

66551166 is a wasteful number, since it uses less digits than its factorization.

66551166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 822 (or 816 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 66551166 is about 8157.8898006776. The cubic root of 66551166 is about 405.2458315478.

Subtracting from 66551166 its reverse (66115566), we obtain a square (435600 = 660²).

The spelling of 66551166 in words is "sixty-six million, five hundred fifty-one thousand, one hundred sixty-six".