505501891 has 2 divisors, whose sum is σ = 505501892. Its totient is φ = 505501890.

The previous prime is 505501861. The next prime is 505501921. The reversal of 505501891 is 198105505.

It is a balanced prime because it is at equal distance from previous prime (505501861) and next prime (505501921).

It is a cyclic number.

It is not a de Polignac number, because 505501891 - 2⁹ = 505501379 is a prime.

It is not a weakly prime, because it can be changed into another prime (505501811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 252750945 + 252750946.

It is an arithmetic number, because the mean of its divisors is an integer number (252750946).

Almost surely, 2^505501891 is an apocalyptic number.

505501891 is a deficient number, since it is larger than the sum of its proper divisors (1).

505501891 is an equidigital number, since it uses as much as digits as its factorization.

505501891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9000, while the sum is 34.

The square root of 505501891 is about 22483.3692092622. The cubic root of 505501891 is about 796.6011484393.

It can be divided in two parts, 50550 and 1891, that added together give a square (52441 = 229²).

The spelling of 505501891 in words is "five hundred five million, five hundred one thousand, eight hundred ninety-one".