561423 has 4 divisors (see below), whose sum is σ = 748568. Its totient is φ = 374280.

The previous prime is 561419. The next prime is 561439. The reversal of 561423 is 324165.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 561423 - 2² = 561419 is a prime.

It is a D-number.

It is a Duffinian number.

561423 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 561423.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561923) 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, 93568 + ... + 93573.

It is an arithmetic number, because the mean of its divisors is an integer number (187142).

2⁵⁶¹⁴²³ is an apocalyptic number.

561423 is a deficient number, since it is larger than the sum of its proper divisors (187145).

561423 is a wasteful number, since it uses less digits than its factorization.

561423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187144.

The product of its digits is 720, while the sum is 21.

The square root of 561423 is about 749.2816559879. The cubic root of 561423 is about 82.4954634787.

Adding to 561423 its reverse (324165), we get a palindrome (885588).

The spelling of 561423 in words is "five hundred sixty-one thousand, four hundred twenty-three".