409061561 has 2 divisors, whose sum is σ = 409061562. Its totient is φ = 409061560.

The previous prime is 409061519. The next prime is 409061563. The reversal of 409061561 is 165160904.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 378535936 + 30525625 = 19456^2 + 5525^2 .

It is a cyclic number.

It is not a de Polignac number, because 409061561 - 2²⁶ = 341952697 is a prime.

Together with 409061563, 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 (409061563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 204530780 + 204530781.

It is an arithmetic number, because the mean of its divisors is an integer number (204530781).

Almost surely, 2^409061561 is an apocalyptic number.

It is an amenable number.

409061561 is a deficient number, since it is larger than the sum of its proper divisors (1).

409061561 is an equidigital number, since it uses as much as digits as its factorization.

409061561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 409061561 is about 20225.2703566603. The cubic root of 409061561 is about 742.3286523934.

The spelling of 409061561 in words is "four hundred nine million, sixty-one thousand, five hundred sixty-one".