690665 has 8 divisors (see below), whose sum is σ = 846720. Its totient is φ = 540592.

The previous prime is 690661. The next prime is 690673. The reversal of 690665 is 566096.

690665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 690665 - 2² = 690661 is a prime.

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (690661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1235 + ... + 1704.

It is an arithmetic number, because the mean of its divisors is an integer number (105840).

2⁶⁹⁰⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

690665 is a deficient number, since it is larger than the sum of its proper divisors (156055).

690665 is a wasteful number, since it uses less digits than its factorization.

690665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2991.

The product of its (nonzero) digits is 9720, while the sum is 32.

The square root of 690665 is about 831.0625728548. The cubic root of 690665 is about 88.3939380786.

The spelling of 690665 in words is "six hundred ninety thousand, six hundred sixty-five".