669399 has 4 divisors (see below), whose sum is σ = 892536. Its totient is φ = 446264.

The previous prime is 669391. The next prime is 669401. The reversal of 669399 is 993966.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 669399 - 2³ = 669391 is a prime.

It is a D-number.

It is a self number, because there is not a number n which added to its sum of digits gives 669399.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669391) 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, 111564 + ... + 111569.

It is an arithmetic number, because the mean of its divisors is an integer number (223134).

2⁶⁶⁹³⁹⁹ is an apocalyptic number.

669399 is a deficient number, since it is larger than the sum of its proper divisors (223137).

669399 is a wasteful number, since it uses less digits than its factorization.

669399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223136.

The product of its digits is 78732, while the sum is 42.

The square root of 669399 is about 818.1680756422. The cubic root of 669399 is about 87.4772294490.

The spelling of 669399 in words is "six hundred sixty-nine thousand, three hundred ninety-nine".