690605 has 8 divisors (see below), whose sum is σ = 851352. Its totient is φ = 537408.

The previous prime is 690589. The next prime is 690607. The reversal of 690605 is 506096.

690605 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 203401 + 487204 = 451^2 + 698^2 .

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 690605 - 2⁴ = 690589 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (690607) 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, 1682 + ... + 2051.

It is an arithmetic number, because the mean of its divisors is an integer number (106419).

2⁶⁹⁰⁶⁰⁵ is an apocalyptic number.

It is an amenable number.

690605 is a deficient number, since it is larger than the sum of its proper divisors (160747).

690605 is a wasteful number, since it uses less digits than its factorization.

690605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3775.

The product of its (nonzero) digits is 1620, while the sum is 26.

The square root of 690605 is about 831.0264737059. The cubic root of 690605 is about 88.3913783283.

The spelling of 690605 in words is "six hundred ninety thousand, six hundred five".