561291 has 8 divisors (see below), whose sum is σ = 752640. Its totient is φ = 372072.

The previous prime is 561277. The next prime is 561307. The reversal of 561291 is 192165.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 561291 - 2¹¹ = 559243 is a prime.

It is not an unprimeable number, because it can be changed into a prime (561251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 250 + ... + 1088.

It is an arithmetic number, because the mean of its divisors is an integer number (94080).

2⁵⁶¹²⁹¹ is an apocalyptic number.

561291 is a deficient number, since it is larger than the sum of its proper divisors (191349).

561291 is a wasteful number, since it uses less digits than its factorization.

561291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1065.

The product of its digits is 540, while the sum is 24.

The square root of 561291 is about 749.1935664433. The cubic root of 561291 is about 82.4889976145.

The spelling of 561291 in words is "five hundred sixty-one thousand, two hundred ninety-one".