505501055981 has 2 divisors, whose sum is σ = 505501055982. Its totient is φ = 505501055980.

The previous prime is 505501055947. The next prime is 505501056001. The reversal of 505501055981 is 189550105505.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 326035290025 + 179465765956 = 570995^2 + 423634^2 .

It is a cyclic number.

It is not a de Polignac number, because 505501055981 - 2¹⁰ = 505501054957 is a prime.

It is a super-2 number, since 2×505501055981² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (505501055921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 252750527990 + 252750527991.

It is an arithmetic number, because the mean of its divisors is an integer number (252750527991).

Almost surely, 2^505501055981 is an apocalyptic number.

It is an amenable number.

505501055981 is a deficient number, since it is larger than the sum of its proper divisors (1).

505501055981 is an equidigital number, since it uses as much as digits as its factorization.

505501055981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 225000, while the sum is 44.

The spelling of 505501055981 in words is "five hundred five billion, five hundred one million, fifty-five thousand, nine hundred eighty-one".