505455723781 has 2 divisors, whose sum is σ = 505455723782. Its totient is φ = 505455723780.

The previous prime is 505455723779. The next prime is 505455723809. The reversal of 505455723781 is 187327554505.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 296190646756 + 209265077025 = 544234^2 + 457455^2 .

It is a cyclic number.

It is not a de Polignac number, because 505455723781 - 2¹ = 505455723779 is a prime.

It is a super-2 number, since 2×505455723781² (a number of 24 digits) contains 22 as substring.

Together with 505455723779, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (505455723281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 252727861890 + 252727861891.

It is an arithmetic number, because the mean of its divisors is an integer number (252727861891).

Almost surely, 2^505455723781 is an apocalyptic number.

It is an amenable number.

505455723781 is a deficient number, since it is larger than the sum of its proper divisors (1).

505455723781 is an equidigital number, since it uses as much as digits as its factorization.

505455723781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5880000, while the sum is 52.

The spelling of 505455723781 in words is "five hundred five billion, four hundred fifty-five million, seven hundred twenty-three thousand, seven hundred eighty-one".