561239 has 4 divisors (see below), whose sum is σ = 641424. Its totient is φ = 481056.

The previous prime is 561229. The next prime is 561251. The reversal of 561239 is 932165.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-561239 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561229) 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, 40082 + ... + 40095.

It is an arithmetic number, because the mean of its divisors is an integer number (160356).

2⁵⁶¹²³⁹ is an apocalyptic number.

561239 is a deficient number, since it is larger than the sum of its proper divisors (80185).

561239 is an equidigital number, since it uses as much as digits as its factorization.

561239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80184.

The product of its digits is 1620, while the sum is 26.

The square root of 561239 is about 749.1588616575. The cubic root of 561239 is about 82.4864501775.

The spelling of 561239 in words is "five hundred sixty-one thousand, two hundred thirty-nine".