55775509 has 2 divisors, whose sum is σ = 55775510. Its totient is φ = 55775508.

The previous prime is 55775413. The next prime is 55775513. The reversal of 55775509 is 90557755.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55726225 + 49284 = 7465^2 + 222^2 .

It is a cyclic number.

It is not a de Polignac number, because 55775509 - 2⁹ = 55774997 is a prime.

It is a super-2 number, since 2×55775509² = 6221814808418162, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55775549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27887754 + 27887755.

It is an arithmetic number, because the mean of its divisors is an integer number (27887755).

Almost surely, 2^55775509 is an apocalyptic number.

It is an amenable number.

55775509 is a deficient number, since it is larger than the sum of its proper divisors (1).

55775509 is an equidigital number, since it uses as much as digits as its factorization.

55775509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 275625, while the sum is 43.

The square root of 55775509 is about 7468.3002751630. The cubic root of 55775509 is about 382.0743187548.

The spelling of 55775509 in words is "fifty-five million, seven hundred seventy-five thousand, five hundred nine".