561382909 has 2 divisors, whose sum is σ = 561382910. Its totient is φ = 561382908.

The previous prime is 561382901. The next prime is 561382933. The reversal of 561382909 is 909283165.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 517426009 + 43956900 = 22747^2 + 6630^2 .

It is a cyclic number.

It is not a de Polignac number, because 561382909 - 2³ = 561382901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561382901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280691454 + 280691455.

It is an arithmetic number, because the mean of its divisors is an integer number (280691455).

Almost surely, 2^561382909 is an apocalyptic number.

It is an amenable number.

561382909 is a deficient number, since it is larger than the sum of its proper divisors (1).

561382909 is an equidigital number, since it uses as much as digits as its factorization.

561382909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 116640, while the sum is 43.

The square root of 561382909 is about 23693.5204011561. The cubic root of 561382909 is about 824.9349977558.

The spelling of 561382909 in words is "five hundred sixty-one million, three hundred eighty-two thousand, nine hundred nine".