666644522 has 16 divisors (see below), whose sum is σ = 1054190592. Its totient is φ = 315705360.

The previous prime is 666644521. The next prime is 666644551. The reversal of 666644522 is 225446666.

It is a self number, because there is not a number n which added to its sum of digits gives 666644522.

It is not an unprimeable number, because it can be changed into a prime (666644521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 111473 + ... + 117300.

It is an arithmetic number, because the mean of its divisors is an integer number (65886912).

Almost surely, 2^666644522 is an apocalyptic number.

666644522 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

666644522 is a deficient number, since it is larger than the sum of its proper divisors (387546070).

666644522 is a wasteful number, since it uses less digits than its factorization.

666644522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228853.

The product of its digits is 414720, while the sum is 41.

The square root of 666644522 is about 25819.4601415289. The cubic root of 666644522 is about 873.5707920551.

The spelling of 666644522 in words is "six hundred sixty-six million, six hundred forty-four thousand, five hundred twenty-two".