669479989 has 2 divisors, whose sum is σ = 669479990. Its totient is φ = 669479988.

The previous prime is 669479947. The next prime is 669480037. The reversal of 669479989 is 989974966.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 529460100 + 140019889 = 23010^2 + 11833^2 .

It is a cyclic number.

It is not a de Polignac number, because 669479989 - 2¹⁹ = 668955701 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (669479189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334739994 + 334739995.

It is an arithmetic number, because the mean of its divisors is an integer number (334739995).

Almost surely, 2^669479989 is an apocalyptic number.

It is an amenable number.

669479989 is a deficient number, since it is larger than the sum of its proper divisors (1).

669479989 is an equidigital number, since it uses as much as digits as its factorization.

669479989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 52907904, while the sum is 67.

The square root of 669479989 is about 25874.3113724791. The cubic root of 669479989 is about 874.8075719433.

The spelling of 669479989 in words is "six hundred sixty-nine million, four hundred seventy-nine thousand, nine hundred eighty-nine".