690666 has 16 divisors (see below), whose sum is σ = 1413984. Its totient is φ = 224784.

The previous prime is 690661. The next prime is 690673. The reversal of 690666 is 666096.

690666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a nialpdrome in base 15.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 690666.

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, 1081 + ... + 1596.

It is an arithmetic number, because the mean of its divisors is an integer number (88374).

2⁶⁹⁰⁶⁶⁶ is an apocalyptic number.

690666 is an abundant number, since it is smaller than the sum of its proper divisors (723318).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

690666 is a wasteful number, since it uses less digits than its factorization.

690666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2725.

The product of its (nonzero) digits is 11664, while the sum is 33.

The square root of 690666 is about 831.0631744940. The cubic root of 690666 is about 88.3939807399.

The spelling of 690666 in words is "six hundred ninety thousand, six hundred sixty-six".