505556557221 has 16 divisors (see below), whose sum is σ = 713742624000. Its totient is φ = 317204971008.

The previous prime is 505556557151. The next prime is 505556557223. The reversal of 505556557221 is 122755655505.

It is not a de Polignac number, because 505556557221 - 2⁹ = 505556556709 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (505556557223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3207385 + ... + 3361313.

It is an arithmetic number, because the mean of its divisors is an integer number (44608914000).

Almost surely, 2^505556557221 is an apocalyptic number.

505556557221 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

It is an amenable number.

505556557221 is a deficient number, since it is larger than the sum of its proper divisors (208186066779).

505556557221 is a wasteful number, since it uses less digits than its factorization.

505556557221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218348.

The product of its (nonzero) digits is 2625000, while the sum is 48.

The spelling of 505556557221 in words is "five hundred five billion, five hundred fifty-six million, five hundred fifty-seven thousand, two hundred twenty-one".