56618209 has 2 divisors, whose sum is σ = 56618210. Its totient is φ = 56618208.

The previous prime is 56618207. The next prime is 56618231. The reversal of 56618209 is 90281665.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 41563809 + 15054400 = 6447^2 + 3880^2 .

It is a cyclic number.

It is not a de Polignac number, because 56618209 - 2¹ = 56618207 is a prime.

Together with 56618207, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (56618207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28309104 + 28309105.

It is an arithmetic number, because the mean of its divisors is an integer number (28309105).

Almost surely, 2^56618209 is an apocalyptic number.

It is an amenable number.

56618209 is a deficient number, since it is larger than the sum of its proper divisors (1).

56618209 is an equidigital number, since it uses as much as digits as its factorization.

56618209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 56618209 is about 7524.5072263903. The cubic root of 56618209 is about 383.9889342333.

The spelling of 56618209 in words is "fifty-six million, six hundred eighteen thousand, two hundred nine".