666222420 has 48 divisors (see below), whose sum is σ = 1868485248. Its totient is φ = 177367680.

The previous prime is 666222397. The next prime is 666222421. The reversal of 666222420 is 24222666.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666222421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29062 + ... + 46658.

It is an arithmetic number, because the mean of its divisors is an integer number (38926776).

Almost surely, 2^666222420 is an apocalyptic number.

666222420 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

666222420 is an abundant number, since it is smaller than the sum of its proper divisors (1202262828).

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

666222420 is a wasteful number, since it uses less digits than its factorization.

666222420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18240 (or 18238 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 30.

The square root of 666222420 is about 25811.2847413685. The cubic root of 666222420 is about 873.3863790142.

The spelling of 666222420 in words is "six hundred sixty-six million, two hundred twenty-two thousand, four hundred twenty".