561878489 has 2 divisors, whose sum is σ = 561878490. Its totient is φ = 561878488.

The previous prime is 561878479. The next prime is 561878497. The reversal of 561878489 is 984878165.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 540097600 + 21780889 = 23240^2 + 4667^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-561878489 is a prime.

It is not a weakly prime, because it can be changed into another prime (561878479) 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 as a sum of consecutive naturals, namely, 280939244 + 280939245.

It is an arithmetic number, because the mean of its divisors is an integer number (280939245).

Almost surely, 2^561878489 is an apocalyptic number.

It is an amenable number.

561878489 is a deficient number, since it is larger than the sum of its proper divisors (1).

561878489 is an equidigital number, since it uses as much as digits as its factorization.

561878489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3870720, while the sum is 56.

The square root of 561878489 is about 23703.9762276290. The cubic root of 561878489 is about 825.1776729058.

The spelling of 561878489 in words is "five hundred sixty-one million, eight hundred seventy-eight thousand, four hundred eighty-nine".