669739 has 8 divisors (see below), whose sum is σ = 770528. Its totient is φ = 570240.

The previous prime is 669733. The next prime is 669763. The reversal of 669739 is 937966.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 669739 - 2⁵ = 669707 is a prime.

It is an Ulam number.

It is a Duffinian number.

669739 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (669733) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1489 + ... + 1885.

It is an arithmetic number, because the mean of its divisors is an integer number (96316).

2⁶⁶⁹⁷³⁹ is an apocalyptic number.

669739 is a deficient number, since it is larger than the sum of its proper divisors (100789).

669739 is a wasteful number, since it uses less digits than its factorization.

669739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 645.

The product of its digits is 61236, while the sum is 40.

The square root of 669739 is about 818.3758305326. The cubic root of 669739 is about 87.4920373706.

The spelling of 669739 in words is "six hundred sixty-nine thousand, seven hundred thirty-nine".