505555005551 has 4 divisors (see below), whose sum is σ = 506301763992. Its totient is φ = 504808247112.

The previous prime is 505555005547. The next prime is 505555005559. The reversal of 505555005551 is 155500555505.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 505555005551 - 2² = 505555005547 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 505555005499 and 505555005508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (505555005559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 373378205 + ... + 373379558.

It is an arithmetic number, because the mean of its divisors is an integer number (126575440998).

Almost surely, 2^505555005551 is an apocalyptic number.

505555005551 is a deficient number, since it is larger than the sum of its proper divisors (746758441).

505555005551 is an equidigital number, since it uses as much as digits as its factorization.

505555005551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 746758440.

The product of its (nonzero) digits is 390625, while the sum is 41.

The spelling of 505555005551 in words is "five hundred five billion, five hundred fifty-five million, five thousand, five hundred fifty-one".