689684 has 6 divisors (see below), whose sum is σ = 1206954. Its totient is φ = 344840.

The previous prime is 689641. The next prime is 689693. The reversal of 689684 is 486986.

It can be written as a sum of positive squares in only one way, i.e., 688900 + 784 = 830^2 + 28^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86207 + ... + 86214.

It is an arithmetic number, because the mean of its divisors is an integer number (201159).

2⁶⁸⁹⁶⁸⁴ is an apocalyptic number.

It is an amenable number.

689684 is a deficient number, since it is larger than the sum of its proper divisors (517270).

689684 is a wasteful number, since it uses less digits than its factorization.

689684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172425 (or 172423 counting only the distinct ones).

The product of its digits is 82944, while the sum is 41.

The square root of 689684 is about 830.4721548613. The cubic root of 689684 is about 88.3520675426.

Adding to 689684 its sum of digits (41), we get a triangular number (689725 = T₁₁₇₄).

The spelling of 689684 in words is "six hundred eighty-nine thousand, six hundred eighty-four".