505545055621 has 2 divisors, whose sum is σ = 505545055622. Its totient is φ = 505545055620.

The previous prime is 505545055619. The next prime is 505545055649. The reversal of 505545055621 is 126550545505.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 374316370596 + 131228685025 = 611814^2 + 362255^2 .

It is a cyclic number.

It is not a de Polignac number, because 505545055621 - 2¹ = 505545055619 is a prime.

Together with 505545055619, 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 (505545055321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 252772527810 + 252772527811.

It is an arithmetic number, because the mean of its divisors is an integer number (252772527811).

Almost surely, 2^505545055621 is an apocalyptic number.

It is an amenable number.

505545055621 is a deficient number, since it is larger than the sum of its proper divisors (1).

505545055621 is an equidigital number, since it uses as much as digits as its factorization.

505545055621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 750000, while the sum is 43.

The spelling of 505545055621 in words is "five hundred five billion, five hundred forty-five million, fifty-five thousand, six hundred twenty-one".