669597509 has 4 divisors (see below), whose sum is σ = 765254304. Its totient is φ = 573940716.

The previous prime is 669597503. The next prime is 669597517. The reversal of 669597509 is 905795966.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 669597509 - 2¹² = 669593413 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669597503) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47828387 + ... + 47828400.

It is an arithmetic number, because the mean of its divisors is an integer number (191313576).

Almost surely, 2^669597509 is an apocalyptic number.

It is an amenable number.

669597509 is a deficient number, since it is larger than the sum of its proper divisors (95656795).

669597509 is an equidigital number, since it uses as much as digits as its factorization.

669597509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95656794.

The product of its (nonzero) digits is 4592700, while the sum is 56.

The square root of 669597509 is about 25876.5822511397. The cubic root of 669597509 is about 874.8587566302.

The spelling of 669597509 in words is "six hundred sixty-nine million, five hundred ninety-seven thousand, five hundred nine".