505500091 has 4 divisors (see below), whose sum is σ = 505575000. Its totient is φ = 505425184.

The previous prime is 505500089. The next prime is 505500101. The reversal of 505500091 is 190005505.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 190005505 = 5 ⋅38001101.

It is a cyclic number.

It is not a de Polignac number, because 505500091 - 2¹ = 505500089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (505500041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26206 + ... + 41203.

It is an arithmetic number, because the mean of its divisors is an integer number (126393750).

Almost surely, 2^505500091 is an apocalyptic number.

505500091 is a deficient number, since it is larger than the sum of its proper divisors (74909).

505500091 is an equidigital number, since it uses as much as digits as its factorization.

505500091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74908.

The product of its (nonzero) digits is 1125, while the sum is 25.

The square root of 505500091 is about 22483.3291796389. The cubic root of 505500091 is about 796.6002029211.

Adding to 505500091 its reverse (190005505), we get a palindrome (695505596).

The spelling of 505500091 in words is "five hundred five million, five hundred thousand, ninety-one".