690440 has 32 divisors (see below), whose sum is σ = 1595160. Its totient is φ = 268800.

The previous prime is 690439. The next prime is 690449. The reversal of 690440 is 44096.

It can be written as a sum of positive squares in 4 ways, for example, as 139876 + 550564 = 374^2 + 742^2 .

It is a Smith number, since the sum of its digits (23) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (690449) 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, 1430 + ... + 1850.

2⁶⁹⁰⁴⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 690440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (797580).

690440 is an abundant number, since it is smaller than the sum of its proper divisors (904720).

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

690440 is a wasteful number, since it uses less digits than its factorization.

690440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 473 (or 469 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 690440 is about 830.9271929598. The cubic root of 690440 is about 88.3843382503.

The spelling of 690440 in words is "six hundred ninety thousand, four hundred forty".