690565 has 4 divisors (see below), whose sum is σ = 828684. Its totient is φ = 552448.

The previous prime is 690553. The next prime is 690583. The reversal of 690565 is 565096.

It is a happy number.

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 247009 + 443556 = 497^2 + 666^2 .

It is a cyclic number.

It is not a de Polignac number, because 690565 - 2⁵ = 690533 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69052 + ... + 69061.

It is an arithmetic number, because the mean of its divisors is an integer number (207171).

2⁶⁹⁰⁵⁶⁵ is an apocalyptic number.

It is an amenable number.

690565 is a deficient number, since it is larger than the sum of its proper divisors (138119).

690565 is a wasteful number, since it uses less digits than its factorization.

690565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138118.

The product of its (nonzero) digits is 8100, while the sum is 31.

The square root of 690565 is about 831.0024067354. The cubic root of 690565 is about 88.3896717457.

The spelling of 690565 in words is "six hundred ninety thousand, five hundred sixty-five".