561612109 has 2 divisors, whose sum is σ = 561612110. Its totient is φ = 561612108.

The previous prime is 561612101. The next prime is 561612179. The reversal of 561612109 is 901216165.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 313644100 + 247968009 = 17710^2 + 15747^2 .

It is a cyclic number.

It is not a de Polignac number, because 561612109 - 2³ = 561612101 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561612101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280806054 + 280806055.

It is an arithmetic number, because the mean of its divisors is an integer number (280806055).

Almost surely, 2^561612109 is an apocalyptic number.

It is an amenable number.

561612109 is a deficient number, since it is larger than the sum of its proper divisors (1).

561612109 is an equidigital number, since it uses as much as digits as its factorization.

561612109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 31.

The square root of 561612109 is about 23698.3566729847. The cubic root of 561612109 is about 825.0472499415.

The spelling of 561612109 in words is "five hundred sixty-one million, six hundred twelve thousand, one hundred nine".