561669391 has 2 divisors, whose sum is σ = 561669392. Its totient is φ = 561669390.

The previous prime is 561669349. The next prime is 561669463. The reversal of 561669391 is 193966165.

561669391 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 561669391 - 2¹⁵ = 561636623 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561669301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280834695 + 280834696.

It is an arithmetic number, because the mean of its divisors is an integer number (280834696).

Almost surely, 2^561669391 is an apocalyptic number.

561669391 is a deficient number, since it is larger than the sum of its proper divisors (1).

561669391 is an equidigital number, since it uses as much as digits as its factorization.

561669391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 262440, while the sum is 46.

The square root of 561669391 is about 23699.5652069822. The cubic root of 561669391 is about 825.0752994019.

The spelling of 561669391 in words is "five hundred sixty-one million, six hundred sixty-nine thousand, three hundred ninety-one".