666235220 has 24 divisors (see below), whose sum is σ = 1598964864. Its totient is φ = 228423456.

The previous prime is 666235217. The next prime is 666235237. The reversal of 666235220 is 22532666.

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 7 ways as a sum of consecutive naturals, for example, 2379272 + ... + 2379551.

It is an arithmetic number, because the mean of its divisors is an integer number (66623536).

Almost surely, 2^666235220 is an apocalyptic number.

It is an amenable number.

666235220 is an abundant number, since it is smaller than the sum of its proper divisors (932729644).

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

666235220 is a wasteful number, since it uses less digits than its factorization.

666235220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4758839 (or 4758837 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 32.

The square root of 666235220 is about 25811.5326937398. The cubic root of 666235220 is about 873.3919723785.

Adding to 666235220 its reverse (22532666), we get a palindrome (688767886).

The spelling of 666235220 in words is "six hundred sixty-six million, two hundred thirty-five thousand, two hundred twenty".