55385509 has 2 divisors, whose sum is σ = 55385510. Its totient is φ = 55385508.

The previous prime is 55385479. The next prime is 55385521. The reversal of 55385509 is 90558355.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54434884 + 950625 = 7378^2 + 975^2 .

It is a cyclic number.

It is not a de Polignac number, because 55385509 - 2¹³ = 55377317 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55385569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27692754 + 27692755.

It is an arithmetic number, because the mean of its divisors is an integer number (27692755).

Almost surely, 2^55385509 is an apocalyptic number.

It is an amenable number.

55385509 is a deficient number, since it is larger than the sum of its proper divisors (1).

55385509 is an equidigital number, since it uses as much as digits as its factorization.

55385509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 135000, while the sum is 40.

The square root of 55385509 is about 7442.1441130900. The cubic root of 55385509 is about 381.1817068752.

The spelling of 55385509 in words is "fifty-five million, three hundred eighty-five thousand, five hundred nine".