561121279 has 4 divisors (see below), whose sum is σ = 568224160. Its totient is φ = 554018400.

The previous prime is 561121277. The next prime is 561121291. The reversal of 561121279 is 972121165.

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

It is a cyclic number.

It is not a de Polignac number, because 561121279 - 2¹ = 561121277 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561121273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3551322 + ... + 3551479.

It is an arithmetic number, because the mean of its divisors is an integer number (142056040).

Almost surely, 2^561121279 is an apocalyptic number.

561121279 is a deficient number, since it is larger than the sum of its proper divisors (7102881).

561121279 is an equidigital number, since it uses as much as digits as its factorization.

561121279 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7102880.

The product of its digits is 7560, while the sum is 34.

The square root of 561121279 is about 23687.9986279973. The cubic root of 561121279 is about 824.8068254174.

The spelling of 561121279 in words is "five hundred sixty-one million, one hundred twenty-one thousand, two hundred seventy-nine".