669390949 has 2 divisors, whose sum is σ = 669390950. Its totient is φ = 669390948.

The previous prime is 669390941. The next prime is 669390973. The reversal of 669390949 is 949093966.

669390949 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 594481924 + 74909025 = 24382^2 + 8655^2 .

It is a cyclic number.

It is not a de Polignac number, because 669390949 - 2³ = 669390941 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 669390949.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (669390941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334695474 + 334695475.

It is an arithmetic number, because the mean of its divisors is an integer number (334695475).

Almost surely, 2^669390949 is an apocalyptic number.

It is an amenable number.

669390949 is a deficient number, since it is larger than the sum of its proper divisors (1).

669390949 is an equidigital number, since it uses as much as digits as its factorization.

669390949 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2834352, while the sum is 55.

The square root of 669390949 is about 25872.5906897628. The cubic root of 669390949 is about 874.7687874533.

The spelling of 669390949 in words is "six hundred sixty-nine million, three hundred ninety thousand, nine hundred forty-nine".