669406 has 8 divisors (see below), whose sum is σ = 1009800. Its totient is φ = 332808.

The previous prime is 669401. The next prime is 669413. The reversal of 669406 is 604966.

669406 = T₃₂₈ + T₃₂₉ + ... + T₃₃₉.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669401) 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, 456 + ... + 1243.

It is an arithmetic number, because the mean of its divisors is an integer number (126225).

2⁶⁶⁹⁴⁰⁶ is an apocalyptic number.

669406 is a deficient number, since it is larger than the sum of its proper divisors (340394).

669406 is a wasteful number, since it uses less digits than its factorization.

669406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1898.

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 669406 is about 818.1723534806. The cubic root of 669406 is about 87.4775343685.

The spelling of 669406 in words is "six hundred sixty-nine thousand, four hundred six".