551125021 has 2 divisors, whose sum is σ = 551125022. Its totient is φ = 551125020.

The previous prime is 551125013. The next prime is 551125073. The reversal of 551125021 is 120521155.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 434722500 + 116402521 = 20850^2 + 10789^2 .

It is a cyclic number.

It is not a de Polignac number, because 551125021 - 2³ = 551125013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 551124983 and 551125001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (551125621) 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 as a sum of consecutive naturals, namely, 275562510 + 275562511.

It is an arithmetic number, because the mean of its divisors is an integer number (275562511).

Almost surely, 2^551125021 is an apocalyptic number.

It is an amenable number.

551125021 is a deficient number, since it is larger than the sum of its proper divisors (1).

551125021 is an equidigital number, since it uses as much as digits as its factorization.

551125021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 500, while the sum is 22.

The square root of 551125021 is about 23476.0520744013. The cubic root of 551125021 is about 819.8795287026.

Adding to 551125021 its reverse (120521155), we get a palindrome (671646176).

The spelling of 551125021 in words is "five hundred fifty-one million, one hundred twenty-five thousand, twenty-one".