669949966 has 16 divisors (see below), whose sum is σ = 1148819040. Its totient is φ = 287038080.

The previous prime is 669949949. The next prime is 669949979.

669949966 is nontrivially palindromic in base 10.

669949966 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 669949898 and 669949907.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84826 + ... + 92386.

It is an arithmetic number, because the mean of its divisors is an integer number (71801190).

Almost surely, 2^669949966 is an apocalyptic number.

669949966 is a deficient number, since it is larger than the sum of its proper divisors (478869074).

669949966 is a wasteful number, since it uses less digits than its factorization.

669949966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13899.

The product of its digits is 34012224, while the sum is 64.

The square root of 669949966 is about 25883.3917020162. The cubic root of 669949966 is about 875.0122299243.

It can be divided in two parts, 6699 and 49966, that added together give a palindrome (56665).

The spelling of 669949966 in words is "six hundred sixty-nine million, nine hundred forty-nine thousand, nine hundred sixty-six".