690505 has 4 divisors (see below), whose sum is σ = 828612. Its totient is φ = 552400.

The previous prime is 690493. The next prime is 690509. The reversal of 690505 is 505096.

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 132496 + 558009 = 364^2 + 747^2 .

It is not a de Polignac number, because 690505 - 2⁷ = 690377 is a prime.

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

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 690505.

It is not an unprimeable number, because it can be changed into a prime (690509) 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, 69046 + ... + 69055.

It is an arithmetic number, because the mean of its divisors is an integer number (207153).

2⁶⁹⁰⁵⁰⁵ is an apocalyptic number.

It is an amenable number.

690505 is a deficient number, since it is larger than the sum of its proper divisors (138107).

690505 is a wasteful number, since it uses less digits than its factorization.

690505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138106.

The product of its (nonzero) digits is 1350, while the sum is 25.

The square root of 690505 is about 830.9663049727. The cubic root of 690505 is about 88.3871117483.

The spelling of 690505 in words is "six hundred ninety thousand, five hundred five".