561440 has 72 divisors (see below), whose sum is σ = 1508220. Its totient is φ = 197120.

The previous prime is 561439. The next prime is 561461. The reversal of 561440 is 44165.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 559504 + 1936 = 748^2 + 44^2 .

It is a hoax number, since the sum of its digits (20) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19346 + ... + 19374.

2⁵⁶¹⁴⁴⁰ 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 561440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (754110).

561440 is an abundant number, since it is smaller than the sum of its proper divisors (946780).

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

561440 is a wasteful number, since it uses less digits than its factorization.

561440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66 (or 47 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 561440 is about 749.2930001008. The cubic root of 561440 is about 82.4962961300.

It can be divided in two parts, 561 and 440, that added together give a palindrome (1001).

The spelling of 561440 in words is "five hundred sixty-one thousand, four hundred forty".