66889188 has 18 divisors (see below), whose sum is σ = 169081094. Its totient is φ = 22296384.

The previous prime is 66889157. The next prime is 66889189. The reversal of 66889188 is 88198866.

It can be written as a sum of positive squares in only one way, i.e., 41062464 + 25826724 = 6408^2 + 5082^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is not an unprimeable number, because it can be changed into a prime (66889189) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 928981 + ... + 929052.

Almost surely, 2^66889188 is an apocalyptic number.

It is an amenable number.

66889188 is an abundant number, since it is smaller than the sum of its proper divisors (102191906).

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

66889188 is a wasteful number, since it uses less digits than its factorization.

66889188 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1858043 (or 1858038 counting only the distinct ones).

The product of its digits is 1327104, while the sum is 54.

The square root of 66889188 is about 8178.5810505246. The cubic root of 66889188 is about 405.9307719249.

It can be divided in two parts, 6688 and 9188, that added together give a square (15876 = 126²).

The spelling of 66889188 in words is "sixty-six million, eight hundred eighty-nine thousand, one hundred eighty-eight".