555000021 has 12 divisors (see below), whose sum is σ = 814809580. Its totient is φ = 363934080.

The previous prime is 555000007. The next prime is 555000029. The reversal of 555000021 is 120000555.

It can be written as a sum of positive squares in 2 ways, for example, as 144937521 + 410062500 = 12039^2 + 20250^2 .

It is not a de Polignac number, because 555000021 - 2⁵ = 554999989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 554999958 and 555000003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (555000029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 504916 + ... + 506013.

Almost surely, 2^555000021 is an apocalyptic number.

It is an amenable number.

555000021 is a deficient number, since it is larger than the sum of its proper divisors (259809559).

555000021 is a wasteful number, since it uses less digits than its factorization.

555000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1010996 (or 1010993 counting only the distinct ones).

The product of its (nonzero) digits is 250, while the sum is 18.

The square root of 555000021 is about 23558.4384244797. The cubic root of 555000021 is about 821.7965868527.

Adding to 555000021 its reverse (120000555), we get a palindrome (675000576).

The spelling of 555000021 in words is "five hundred fifty-five million, twenty-one", and thus it is an aban number.