55505055581 has 2 divisors, whose sum is σ = 55505055582. Its totient is φ = 55505055580.

The previous prime is 55505055533. The next prime is 55505055587. The reversal of 55505055581 is 18555050555.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48011383225 + 7493672356 = 219115^2 + 86566^2 .

It is a cyclic number.

It is not a de Polignac number, because 55505055581 - 2¹⁰ = 55505054557 is a prime.

It is a super-2 number, since 2×55505055581² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55505055587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27752527790 + 27752527791.

It is an arithmetic number, because the mean of its divisors is an integer number (27752527791).

Almost surely, 2^55505055581 is an apocalyptic number.

It is an amenable number.

55505055581 is a deficient number, since it is larger than the sum of its proper divisors (1).

55505055581 is an equidigital number, since it uses as much as digits as its factorization.

55505055581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 625000, while the sum is 44.

The spelling of 55505055581 in words is "fifty-five billion, five hundred five million, fifty-five thousand, five hundred eighty-one".