669742 has 8 divisors (see below), whose sum is σ = 1009296. Its totient is φ = 333312.

The previous prime is 669733. The next prime is 669763. The reversal of 669742 is 247966.

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

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 669698 and 669707.

It is a congruent number.

It is an unprimeable number.

669742 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 138 + ... + 1165.

It is an arithmetic number, because the mean of its divisors is an integer number (126162).

2⁶⁶⁹⁷⁴² is an apocalyptic number.

669742 is a deficient number, since it is larger than the sum of its proper divisors (339554).

669742 is a wasteful number, since it uses less digits than its factorization.

669742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1562.

The product of its digits is 18144, while the sum is 34.

The square root of 669742 is about 818.3776634293. The cubic root of 669742 is about 87.4921680065.

The spelling of 669742 in words is "six hundred sixty-nine thousand, seven hundred forty-two".