556105021 has 4 divisors (see below), whose sum is σ = 563722972. Its totient is φ = 548487072.

The previous prime is 556104959. The next prime is 556105027. The reversal of 556105021 is 120501655.

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

It can be written as a sum of positive squares in 2 ways, for example, as 184579396 + 371525625 = 13586^2 + 19275^2 .

It is a cyclic number.

It is not a de Polignac number, because 556105021 - 2¹¹ = 556102973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (556105027) 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, 3808866 + ... + 3809011.

It is an arithmetic number, because the mean of its divisors is an integer number (140930743).

Almost surely, 2^556105021 is an apocalyptic number.

It is an amenable number.

556105021 is a deficient number, since it is larger than the sum of its proper divisors (7617951).

556105021 is an equidigital number, since it uses as much as digits as its factorization.

556105021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7617950.

The product of its (nonzero) digits is 1500, while the sum is 25.

The square root of 556105021 is about 23581.8790811928. The cubic root of 556105021 is about 822.3416218057.

Adding to 556105021 its reverse (120501655), we get a palindrome (676606676).

The spelling of 556105021 in words is "five hundred fifty-six million, one hundred five thousand, twenty-one".