55271809 has 2 divisors, whose sum is σ = 55271810. Its totient is φ = 55271808.

The previous prime is 55271807. The next prime is 55271831. The reversal of 55271809 is 90817255.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28387584 + 26884225 = 5328^2 + 5185^2 .

It is a cyclic number.

It is not a de Polignac number, because 55271809 - 2¹ = 55271807 is a prime.

Together with 55271807, it forms a pair of twin primes.

It is equal to p_3297475 and since 55271809 and 3297475 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (55271807) 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, 27635904 + 27635905.

It is an arithmetic number, because the mean of its divisors is an integer number (27635905).

Almost surely, 2^55271809 is an apocalyptic number.

It is an amenable number.

55271809 is a deficient number, since it is larger than the sum of its proper divisors (1).

55271809 is an equidigital number, since it uses as much as digits as its factorization.

55271809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25200, while the sum is 37.

The square root of 55271809 is about 7434.5012610127. The cubic root of 55271809 is about 380.9206876285.

It can be divided in two parts, 552 and 71809, that added together give a square (72361 = 269²).

The spelling of 55271809 in words is "fifty-five million, two hundred seventy-one thousand, eight hundred nine".