66661110 has 64 divisors (see below), whose sum is σ = 179064000. Its totient is φ = 17646336.

The previous prime is 66661109. The next prime is 66661151. The reversal of 66661110 is 1116666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nialpdrome in base 10.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 39402 + ... + 41058.

It is an arithmetic number, because the mean of its divisors is an integer number (2797875).

Almost surely, 2^66661110 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66661110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89532000).

66661110 is an abundant number, since it is smaller than the sum of its proper divisors (112402890).

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

66661110 is a wasteful number, since it uses less digits than its factorization.

66661110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1822 (or 1816 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 66661110 is about 8164.6255272364. The cubic root of 66661110 is about 405.4688671355.

Adding to 66661110 its reverse (1116666), we get a palindrome (67777776).

It can be divided in two parts, 6666 and 1110, that added together give a 5-th power (7776 = 6⁵).

The spelling of 66661110 in words is "sixty-six million, six hundred sixty-one thousand, one hundred ten".