669831 has 4 divisors (see below), whose sum is σ = 893112. Its totient is φ = 446552.

The previous prime is 669791. The next prime is 669839. The reversal of 669831 is 138966.

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 669831 - 2¹⁹ = 145543 is a prime.

It is a super-2 number, since 2×669831² = 897347137122, which contains 22 as substring.

It is a D-number.

It is a junction number, because it is equal to n+sod(n) for n = 669792 and 669801.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 669831.

It is not an unprimeable number, because it can be changed into a prime (669839) 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, 111636 + ... + 111641.

It is an arithmetic number, because the mean of its divisors is an integer number (223278).

2⁶⁶⁹⁸³¹ is an apocalyptic number.

669831 is a deficient number, since it is larger than the sum of its proper divisors (223281).

669831 is a wasteful number, since it uses less digits than its factorization.

669831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223280.

The product of its digits is 7776, while the sum is 33.

The square root of 669831 is about 818.4320374961. The cubic root of 669831 is about 87.4960433585.

It can be divided in two parts, 66 and 9831, that multiplied together give a palindrome (648846).

The spelling of 669831 in words is "six hundred sixty-nine thousand, eight hundred thirty-one".