56551909 has 2 divisors, whose sum is σ = 56551910. Its totient is φ = 56551908.

The previous prime is 56551903. The next prime is 56551921. The reversal of 56551909 is 90915565.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54434884 + 2117025 = 7378^2 + 1455^2 .

It is a cyclic number.

It is not a de Polignac number, because 56551909 - 2²⁵ = 22997477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56551903) 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, 28275954 + 28275955.

It is an arithmetic number, because the mean of its divisors is an integer number (28275955).

Almost surely, 2^56551909 is an apocalyptic number.

It is an amenable number.

56551909 is a deficient number, since it is larger than the sum of its proper divisors (1).

56551909 is an equidigital number, since it uses as much as digits as its factorization.

56551909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60750, while the sum is 40.

The square root of 56551909 is about 7520.1003317775. The cubic root of 56551909 is about 383.8389918352.

The spelling of 56551909 in words is "fifty-six million, five hundred fifty-one thousand, nine hundred nine".