561998819 has 2 divisors, whose sum is σ = 561998820. Its totient is φ = 561998818.

The previous prime is 561998779. The next prime is 561998821. The reversal of 561998819 is 918899165.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 561998819 - 2¹² = 561994723 is a prime.

It is a super-2 number, since 2×561998819² = 631685345114789522, which contains 22 as substring.

Together with 561998821, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (561998119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280999409 + 280999410.

It is an arithmetic number, because the mean of its divisors is an integer number (280999410).

Almost surely, 2^561998819 is an apocalyptic number.

561998819 is a deficient number, since it is larger than the sum of its proper divisors (1).

561998819 is an equidigital number, since it uses as much as digits as its factorization.

561998819 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1399680, while the sum is 56.

The square root of 561998819 is about 23706.5142735072. The cubic root of 561998819 is about 825.2365744560.

The spelling of 561998819 in words is "five hundred sixty-one million, nine hundred ninety-eight thousand, eight hundred nineteen".