689965 has 4 divisors (see below), whose sum is σ = 827964. Its totient is φ = 551968.

The previous prime is 689963. The next prime is 689981. The reversal of 689965 is 569986.

689965 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 84681 + 605284 = 291^2 + 778^2 .

It is a cyclic number.

It is not a de Polignac number, because 689965 - 2¹ = 689963 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (689963) 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, 68992 + ... + 69001.

It is an arithmetic number, because the mean of its divisors is an integer number (206991).

2⁶⁸⁹⁹⁶⁵ is an apocalyptic number.

It is an amenable number.

689965 is a deficient number, since it is larger than the sum of its proper divisors (137999).

689965 is a wasteful number, since it uses less digits than its factorization.

689965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137998.

The product of its digits is 116640, while the sum is 43.

The square root of 689965 is about 830.6413185004. The cubic root of 689965 is about 88.3640650951.

The spelling of 689965 in words is "six hundred eighty-nine thousand, nine hundred sixty-five".