669497509 has 16 divisors (see below), whose sum is σ = 741024000. Its totient is φ = 602320320.

The previous prime is 669497503. The next prime is 669497533. The reversal of 669497509 is 905794966.

It is a cyclic number.

It is not a de Polignac number, because 669497509 - 2¹⁷ = 669366437 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 669497509.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669497503) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23652 + ... + 43570.

It is an arithmetic number, because the mean of its divisors is an integer number (46314000).

Almost surely, 2^669497509 is an apocalyptic number.

It is an amenable number.

669497509 is a deficient number, since it is larger than the sum of its proper divisors (71526491).

669497509 is a wasteful number, since it uses less digits than its factorization.

669497509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20028.

The product of its (nonzero) digits is 3674160, while the sum is 55.

The square root of 669497509 is about 25874.6499299991. The cubic root of 669497509 is about 874.8152029879.

The spelling of 669497509 in words is "six hundred sixty-nine million, four hundred ninety-seven thousand, five hundred nine".