666463221 has 12 divisors (see below), whose sum is σ = 998323872. Its totient is φ = 444308652.

The previous prime is 666463219. The next prime is 666463229. The reversal of 666463221 is 122364666.

It is not a de Polignac number, because 666463221 - 2¹ = 666463219 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666463229) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1371081 + ... + 1371566.

It is an arithmetic number, because the mean of its divisors is an integer number (83193656).

Almost surely, 2^666463221 is an apocalyptic number.

It is an amenable number.

666463221 is a deficient number, since it is larger than the sum of its proper divisors (331860651).

666463221 is an equidigital number, since it uses as much as digits as its factorization.

666463221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2742662 (or 2742650 counting only the distinct ones).

The product of its digits is 62208, while the sum is 36.

The square root of 666463221 is about 25815.9489657072. The cubic root of 666463221 is about 873.4915926153.

The spelling of 666463221 in words is "six hundred sixty-six million, four hundred sixty-three thousand, two hundred twenty-one".